I'm eagerly reading all blue posts and information regarding Cataclysm. I'm one step closer to finding out what I want to play in Cataclysm now. I'm just no paladin. I'm probably no priest either. So most likely it will be something like this in Cataclysm, in order of most likely at the moment.
Shaman as my healer in PVE/PVP, Death Knight as my tank in PVE and dps in PVP.
Druid as tank in PVE and healer in PVP.
Keep all three more or less active.
Druid as my healer in PVE/PVP, Death Knight as my tank in PVE and dps in PVP.
Shaman as my healer, Warrior (!) as my tank in PVE and dps in PVP.
The last alternative is ... very unlikely. But for the moment more likely than playing my paladin. I've just considered levelling one, probably a goblin, to see the new starting zone and enjoy the new levelling experience. I'll probably play the Worgen starting area too. Possibly as a hunter, never had one of those. And then I can retire after the starting area, unless I fiercely fall in love with it.
By the way, just because I'm not going to play a priest or paladin doesn't mean I won't be envying them sometimes...