after just reading the "darkranger for rogues" thread I wondered if they could do the same for all classes with new talent trees..
for example:
Archmage:
when you cast fireball your next arcane blast does +x% dmg, when you cast arcane blast your next frostbolt does +x% dmg, when you cast frostbolt your nextx fireball does +x% dmg... that sort of thing
Archdruid:
a healing/damage hybrid wich works with direct heals and Dot's, roots and wisps do most of it, but also moonlights and throwing leaves that summon an immobile tree at a location cleaving nearby enemies..
Dark ranger:
as mentioned before, a ranged spec for rogues
Ranger:
a healing? or melee spec for hunters.. not much ideas here
dunno:
a melee-shielding/healing spec for paladins.. "holy charge" you charge player X healing everyone near him/her for X and causing your next sacred shield to shield for +100%... that sort of thing.
Shield of Earth:
a shaman tank spec wich works with an aura.. for every totem active you deal X less damage but cause +Y% of the original threat, also take less damage.. also things like increased stamina, convert crit and haste to def and block rating so you can still use hunter/enhancement gear..
just ran out of idea's here but please comment..
oh and yes it'l be hard to balance and won't come with cata but I'm sure that one day we'l all get a 4th talent tree..