Thanks for the replies guys, I should have been more specific.

This team will mostly be for 5 man dungeons, hopefully get as far as possible with them including heroics (and maybe challenge modes) in MoP

For PvP I prefer to take only 3 characters, because I'm not a fan of the 40 man bgs and 3-boxing doesn't hamstring my team by having 5 guys in 1 place at a time in the smaller bgs.

For PvP, I'm currently playing 2 teams,

2 Feral Druids + 1 Resto Druid
2 Arms Warriors + 1 Disc Priest

I'm finding that I enjoy the druids more, from my experience so far in the pre 60 brackets, feral druids do a lot more damage and stealth on all 3 characters is awesome. The Warriorx2+Priest team lives longer though, I'm finding the priest heals super strong compared to the druids.

As for my 5 man, It'll mainly for the challenge of boxing a mixed team (including a mixture of ranged and melee)

Still not completely decided on classes but will most likely go

Plate Tank/Warrior, Ret Pally or DK/Feral Druid or Rogue/Caster/Healer

Hardest thing for me to choose right now is the caster and healer.