Well, I have to say (irregardless of the death of 25 man raiding which I hate) that I don't hold much enthusiasm for my paladin in the coming expansion. Ret is looking good, but that's not really what I want to play as. Holy is a new beast but with a little work could be something fun (really, don't cut illumination, find another way to nerf regen). But Prot is really, really aweful on beta right now.
A large number of talents we're forced to take are unwanted. Massive amount of loss in terms of mitigation and actual abilities (yes, seriously, we have less tools to use to tank with and a lot of the ones we kept just do less - like HoR not doing damage anymore). A clunky and unfun Holy Power mechanic (Ret and Holy make it a lot more fun) -- which btw when we play the stuff for a month before Cata we won't even get Inquisition (level 81) which is really the only useful ability for Prot Holy Power (we'll be forced to use shield which is less useful and even more clunky).
But worst of all, is that there's just no reason to play Prot Paladin when you could be something else. DKs and warriors just blow us away in terms of tanking ability, tools, and talents. Druids bring better hp and mitigation as well as having that healing dual spec with better utility (paladins now only have hand spells--last build judgement of light in addtion to wisdom was dead--while druids have innervate and battle rez). I honestly feel like Cata is worse for prot paladins than vanilla. I was a prot paladin for one of the first Nefarian kills anywhere--back when I had int, mp5, and agi forced on my gear--and Cata Prot Paladins are in a worse position.
