I thought palas weren't that bad at tanking undeads and demons because exorcism works sorta like a taunt in terms of threat gen.
i'm on horde this time so i don't have to worry about palas. suffice to say if you wanna actually tank as a pala, you're best off waiting for tbc as there were places where paladin tanks shined. like morogrim, hyjal waves etc holy wrath works in karazhan because everything is undead. just places where palas were actually good or even the best at aoe snap aggro from consecrate.