Oh, yeah, BGs for sure. Thanks.

Arena: For arena, rogues are amazing for 2's and 3's. However, you must be mindful of who you partner with as some classes are better with rogues than others. If you go to 5's, a shaman could be much more beneficial as a healer or damage.

BG's: In BG's, rogues CAN be one of the most devastating classes if played correctly. They can deal stupid amounts of damage and are very hard to fight off 1v1. Mind you, if the enemy 2v1's you or a healer supports the toon you are attacking, you are screwed. Shaman can be more beneficial teamwise.

Depends if you want to do BG's or Arena. IMO you'll have better luck in 2's and 3's with rogue and anything higher you might wanna do shaman. Also in BG's go shaman that is no question.