Here is some math about cleric's heals speed and cleric specs when Old Ras will come.
I used this calculator to find out the effective heals speed and my Cleric dex stats as example: Dex2 now and Dex2+Mota3+Motarc3 with Old Ras.

Heals Speed

Greater Heal (2,2sec -> 3.1[lvl32] ) | Now = 1,35s - Old Ras = 1,61s
Group spec Heal (2,2sec -> 3.3[lvl36] ) | Now = 1,35s - Old Ras = 1,72s
Minor Heal (2,25sec) | Now = 1,38s - Old Ras= 1,17s
Shear (3,0sec) | Now = 1,84s - Old Ras= 1,56s
Major Heal (3,25sec) | Now = 1,99s - Old Ras= 1,69s
SpreadHeal (3,5sec) | Now = 2,16s - Old Ras= 1,82s

Now: Dex2 (300 dex)
Old Ras: Dex2+Mota3+Motarc3 (312 dex + 9% casting speed)

Purge every 30 mins (for NS) and slower group spec heal will force clerics to spreadheal way more.
Since the Greater Heal becomes slower (Due to 1.69 cap) the Major heal will be used as single heal (It uses less mana). This will probably help clerics with mana pool but still this heal is slower than the Greater Heal we have with New Ras.

Specs

At the moment there are just two possible specs for cleric: 36 rej 40 enh and 33 rej 42 enh.
Since the Major Heal and the SpreadHeal become more important with old ras and there is no more PR/DI new specs might be used. Let's compare them to 36rej 40enh spec (I won't talk about losing yellow resists/defensive proc missing with these specs to make it simple. I assume that everygroup have at least one cleric with 40+ enh for the yellow DQ).

- 40 reg 36 enh (Gains: Yellow spreadheal, 50% Ress. Loses: DQ Shear, Yellow DQ Buff). Bases buffs are not capped if you are lower than 5L0
- 43 reg 32 enh (Gains: Yellow spreadheal, 50% Ress, 100% Single Istant, Yellow Greater Heal (Useless), Red Major Heal. Loses: DQ Shear, Yellow DQ Buff, Yellow SC, Yellow AF, Con/Str/SC Shears). Bases buffs are not capped if you are lower than 9L0


See you Clerics!

You mentioned Mastery of the Arcane.
You will reach the cap of base buffs (62) earlier and improve the specs (up to 93).

vomi wrote:Now: Dex2 (300 dex)
Old Ras: Dex2+Mota3+Motarc3 (312 dex + 9% casting speed)

Old Dex2 equals new Dex2, you'd still have 300 dex I guess.

Razzer wrote:You mentioned Mastery of the Arcane.
You will reach the cap of base buffs (62) earlier and improve the specs (up to 93).

Shouldn't Mastery of the Arcane raise base buffs aswell? Well in case it doesn't that dex is slightly lower than 312.

ana wrote:

vomi wrote:Now: Dex2 (300 dex)
Old Ras: Dex2+Mota3+Motarc3 (312 dex + 9% casting speed)

Old Dex2 equals new Dex2, you'd still have 300 dex I guess.

I suppose I have Mastery of the Arcane 3 (Your “buff” spells will be 9% more effective), so my own dex buffs will be boosted.

vomi wrote:Shouldn't Mastery of the Arcane raise base buffs aswell? Well in case it doesn't that dex is slightly lower than 312.

It does but I guess that "Buffs boosted by this ability are still under the existing spell caps, however." means that the caps 62 and 93 still apply.

vomi wrote:Old Dex2 equals new Dex2, you'd still have 300 dex I guess.
I suppose I have Mastery of the Arcane 3 (Your “buff” spells will be 9% more effective), so my own dex buffs will be boosted.

I thought so in the first place but where do those 12 dex come from then? As a RR8 cleric, you probably will reach 50 enhance so your base buff will only be boosted by 2 points. Where do the other 10 points come from then? Your spec buff surely can't give you another 10 points when it's boosted by those 9%.

ana wrote:

vomi wrote:Shouldn't Mastery of the Arcane raise base buffs aswell? Well in case it doesn't that dex is slightly lower than 312.

It does but I guess that "Buffs boosted by this ability are still under the existing spell caps, however." means that the caps 62 and 93 still apply.

vomi wrote:Old Dex2 equals new Dex2, you'd still have 300 dex I guess.
I suppose I have Mastery of the Arcane 3 (Your “buff” spells will be 9% more effective), so my own dex buffs will be boosted.

I thought so in the first place but where do those 12 dex come from then? As a RR8 cleric, you probably will reach 50 enhance so your base buff will only be boosted by 2 points. Where do the other 10 points come from then? Your spec buff surely can't give you another 10 points when it's boosted by those 9%.

Uhm I didn't know about that cap, so I thought red dex and yellow d/q would have given me +12 dex. I've just checked the real value of red dex + yellow d/q and added that 9%, but apparently is wrong.

vomi wrote:
Since the Major Heal and the SpreadHeal become more important with old ras and there is no more PR/DI new specs might be used.

DI is there, just under a different name (Battery of Life) and with a 30 minutes reuse timer.

Healowner wrote:

vomi wrote:
Since the Major Heal and the SpreadHeal become more important with old ras and there is no more PR/DI new specs might be used.

DI is there, just under a different name (Battery of Life) and with a 30 minutes reuse timer.

I meant: nobody on the earth would spend 10 points to have a 1000hp pool on a 30 minutes timer. So yeah, there is no DI if you are not gimp.

vomi wrote:Uhm I didn't know about that cap, so I thought red dex and yellow d/q would have given me +12 dex. I've just checked the real value of red dex + yellow d/q and added that 9%, but apparently is wrong.

MoA3 will increase your base dex by 2 and your spec dex by 6. It's up to you but I'd not use 10 points to get 8 more dex since they'll reduce your castspeed by only 30-50 ms. There's way better things you can take.

ana wrote:

vomi wrote:Uhm I didn't know about that cap, so I thought red dex and yellow d/q would have given me +12 dex. I've just checked the real value of red dex + yellow d/q and added that 9%, but apparently is wrong.

MoA3 will increase your base dex by 2 and your spec dex by 6. It's up to you but I'd not use 10 points to get 8 more dex since they'll reduce your castspeed by only 30-50 ms. There's way better things you can take.

Well MoA3 doesn't actually only give you more dex. It raises all the buff you make for the whole group. We'll do tests and see anyway if it's worth it!

Vomii wrote:Since the Greater Heal becomes slower (Due to 1.69 cap) the Major heal will be used as single heal (It uses less mana). This will probably help clerics with mana pool but still this heal is slower than the Greater Heal we have with New Ras.

There's one thing you forgot :

1.71 wrote: - Due to the fast paced nature of combat, spread heals were added to the game to make primary healers more effective in many situations, with an emphasis on RvR. Spread heals turned out to be so effective that there is rarely a reason for a primary healer to cast a single target heal. In order to reward primary healers who are judicious in selecting the right heal spell for the situation, as well as to provide a small boost to secondary healing specs, we have reduced the power costs of the following single target heal lines by 33%: Major Restoration (Cleric/Friar), Major Resurgence (Druid/Warden/Bard), Major Somatic Renewal (Mentalist), Major Reconstitution (Healer/Shaman).

Have fun using spread only

Hedra wrote:

Vomii wrote:Since the Greater Heal becomes slower (Due to 1.69 cap) the Major heal will be used as single heal (It uses less mana). This will probably help clerics with mana pool but still this heal is slower than the Greater Heal we have with New Ras.

There's one thing you forgot :

1.71 wrote: - Due to the fast paced nature of combat, spread heals were added to the game to make primary healers more effective in many situations, with an emphasis on RvR. Spread heals turned out to be so effective that there is rarely a reason for a primary healer to cast a single target heal. In order to reward primary healers who are judicious in selecting the right heal spell for the situation, as well as to provide a small boost to secondary healing specs, we have reduced the power costs of the following single target heal lines by 33%: Major Restoration (Cleric/Friar), Major Resurgence (Druid/Warden/Bard), Major Somatic Renewal (Mentalist), Major Reconstitution (Healer/Shaman).

Have fun using spread only

Ahhhh I missed that!

Hedra wrote:

1.71 wrote: - Due to the fast paced nature of combat, spread heals were added to the game to make primary healers more effective in many situations, with an emphasis on RvR. Spread heals turned out to be so effective that there is rarely a reason for a primary healer to cast a single target heal. In order to reward primary healers who are judicious in selecting the right heal spell for the situation, as well as to provide a small boost to secondary healing specs, we have reduced the power costs of the following single target heal lines by 33%: Major Restoration (Cleric/Friar), Major Resurgence (Druid/Warden/Bard), Major Somatic Renewal (Mentalist), Major Reconstitution (Healer/Shaman).

Have fun using spread only

Those 33% do not show up on the Camelotherald, the power costs (10, 15, 20, 24, 30, 39, 48, 58) were never changed until they decided to adjust the heal system in general in 2006. So it kinda seems like this never went live. Not even patch notes or the grab bags are 100% reliable. Guess 1.71 won't change anything about the fact that spread heal will become the most important heal used.