Prot is an interesting idea.
It adds to the attack, and is rather hard to down, can still bubble etc.
A good toon to lead the team with; DK's going IWT/Priority Macro spam.

You still bring some healing to the team.
Decurse is weaker, but the DK's are immune (via abilities) to a lot of crap.

I'll try Prot, and see how it goes (DK's just hit 80th).



For the healing.. I'd think Pally is the best choice at the moment.

But once Resilience/Mitigation catch up to damage...
Disc = Bubble popping, decent heal throughput, some mitigation, strong group heals, decurses, AoE decurse.
Shammy = Heroism, Tremor, Resistance via Healing Stream, Self Rez, Earth Shield.
Pally = Heal throughput, Bubble, Resistance Aura
Druid = HoT and forget, MotW, Thorns vs Melee, Cyclone/Root, Stealth until heals needed.