There's one single log out there of a warrior solo tanking it with a resto shaman having his back and this is with little to no hybrid dps help. We regulary run with 3-4 hybrid, a prot paladin and a disc priest and we have raidcooldowns (both healing and damage reduction) running for every crucial phase (one intermission, some whirls, you name it).
So possible? Yes. Desireable? Probably not (with a warrior tank).