Not sure what I think about the deity changes, although I'm sure the so far negative reactions are subject to change as we work out new strategies. Mysteria's mana boon is basically now +3 MP for 60 piety where before it was +5 MP for 90 piety, which is a fair trade, I think. That's assuming you use Weakening to remove the magic resist - I'm skeptical of the increased magic resistance she adds, because if anything it skews things even more in favor of melee fighters over fireball mages, when probably the opposite is what needed to happen.
Glowing Guardian's Sanctify now seems pretty silly, since it's not worth much piety, it's not worth spending piety for what is usually not very much exp, and Absolution is looking a little bit more attractive as an alternative (but probably still not worth it). Cleansing was rarely useful in the first place, since by the time I'd like to remove negative effects I've usually burned through my piety anyway, but then I suppose that means the increasing cost won't affect too much; the initial cost could probably stand to be reduced, though. And honestly I didn't think Protection needed any changes, so this seems like a bit too much of a nerf - now at endgame, if I have 50+ piety and am worshiping GG I think now I'll be much more likely to just convert to a different deity so I can use potions. If these changes stick, GG needs better alternatives for gaining piety - I think increasing the gain from killing high level enemies would be a good start.
Dracul is potentially going to be more interesting as an early game deity with his much improved resistance boost and the changes to lifesteal, and slightly less useful at the end now that his heal is nerfed. Seems just about right to me. I think his MP boon is probably a little overnerfed, but I'll have to see how easy or hard it is to gain piety from him first.
Taurog's increasing cost for death protection makes me think I'm going to just dump him for Dracul even earlier than usual, especially since healing is a lot more useful to his followers than death protection (why did you spend all that piety on increased resistances if you're just going to take deathblows?). I think what needed to be increased was the piety costs for his sword and shield, since they're currently easy to obtain and tend to be game-breaking at low levels.