Well, the latest changes have hit the servers, which includes the Buff and Debuff stacking system previously mentioned. Also in the patch are a great deal of new cooking recipes, the most fun of which is a food to control critters! Here is the list of known undocumented changes for the Paladin class:
Paladin Class Changes
* Blessing of Might ranks 5+ have all been buffed and now grant more attack power.
* SoW changed to: "Fills the Paladin with divine wisdom for 2 min, giving each melee attack a chance to restore 20168s1% of the paladin's maximum mana. Only one Seal can be active on the Paladin at any one time.
Unleashing this Seal's energy will judge an enemy for 20 sec, granting attacks and spells used against the judged enemy a chance to restore 20268s1% of maximum mana to the attacker. Your melee strikes will refresh the spell's duration. Only one Judgement per Paladin can be active at any one time."
The %ages right now are 4% and 2% respectively.
* Judgements of the Wise (Tier 6) changed to: Your Judgement spells have a 33/66/100% chance to grant up to 10 party or raid members mana regeneration equal to 0.5% of their maximum mana per second.
* Improved Blessing of Might (Tier 1) now increases the attack power bonus from Blessing of Might by 5/10/15/20/25%. (Previously 10/20/30/40/50%)
* Beacon of Light (Tier 11) changed to: The target becomes a Beacon of Light to all targets within a 40 yard radius. Any heals you cast on those targets will also heal the Beacon for 100% of the amount healed.
* Blessing of Sanctuary: Reduces damage taken from all sources by 3% for 30 min. In addition, when the target blocks, parries, or dodges a melee attack the target will gain 10 rage, 20 runic power, or 2% of maximum mana. [There's a Typo in either the tooltip of the implementation. Currently it only restores 1 Rage, not 10].
* Shield Specialization (Tier 3) now increases shield block value by 10/20/30%. (Previously just increased damage absorbed) [This talent still doesn't scale with Block Value gained from Strength. Needs Fixing]
* Toughness (Tier 3) now reduces the duration of all movement slowing effects by 10/20/30/40/50% in addition to its previous effect. (Previously just increased armor by 2/4/6/8/10%)
The change to JoW/SoW is pretty crippling for a Prot or Ret Paladin whose maximum mana is so low. The %ages, given the internal cooldowns, seem to match up with the level of mana regen expected from the new Replenishment mechanic. Furthermore no Paladin has a more or less effective JoW than the other, making a Ret Paladin all the more difficult to justify given that you will have two healing Paladins and they will both be Judging (even from range). As things stand, Ret runs out of mana extremely quickly, have no unique utility, and stand in Melee range taking damage - from a pure convenience perspective they are worse than sub-optimal.
The changes to Beacon of Light are quite something, it should be interesting to see what the Holy Paladins think of it. I'm still not too convinced that it'll work out too well in the field so to speak, mainly because Mana concerns are so much more strict. Duration could also be an issue - losing a GCD every 2 minutes isn't too bad, but losing one every 30 seconds or less may be an issue.
Shield Spec now increasing Block Value is a welcome change which keeps mitigation the same but scales threat for a number of tanking abilities. The new Toughness doesn't stack with Divine Purpose, but if nothing else could be a very interesting PvP talent if you are looking to get deeper in Prot for some reason.
The changes to to Judgement of the Wise and Blessing of Sanctuary were partialy gleaned in the last post, but Blessing of Sanctuary's new secondary effect of replenishing Rage / Runic Power / Mana on a Block, dodge or Parry is very, very significant. Personally, I'd have been happy to see it be simply a 1/1 talent for the Paladin only, restoring mana when he Blocks/Parry's/Dodges - In 5/10-mans you give up BoK by using it on yourself and it's tough to see you using it in a non-raid environment except in situations where you significantly outgear the instance. I'm sure that Tankadins will be fairly pleased with this change to a previously lacklustre spell which now benefits all tanks, but it rightly should renew calls for Blessing of Kings to be moved to Baseline. By itself though it isn't nearly enough to warrant bringing a 3rd Paladin into the fray - in situations were you have 2 Paladins BoW/BoM and BoK will continue to be what's utilised, whether one specs 21pts into Prot or not.
* Glyph of Blessing of Kings -- Reduce the mana cost of your Blessing of Kings and Greater Blessing of Kings spells by 50%.
* Glyph of Sense Undead -- Damage against Undead increased by 1% while your Sense Undead ability
* Glyph of the Warhorse -- Reduce the casting time of your Summon Charger and Summon Warhorse spells by 0.5 sec.
* Glyph of Lay on Hands -- Increases the mana restored by your Lay on Hands spell by 5%.
* Glyph of Blessing of Might -- Increases the duration of your Blessing of Might spell by 20 min when cast on yourself.
* Glyph of Blessing of Wisdom -- Increases the duration of your Blessing of Wisdom spell by 20 min when cast on yourself.
My guess is that these are minor glyphs (though Glyph of Sense Undead could be a Lesser one). The minor Blessing glyphs are pretty disappointing TBH, GotWarhorse and Lay on Hands are not too much better. A full list of Paladin Glyphs datamined so far can be found here.
If there's anything more I'll endeavour to update this list, the patch is still downloading for me.