I am not sure about shadow priests for 5 boxing.

Sure they can produce some nice damage and they probably mow through thrash mobs but I think it will be really hard to do BC instances. Thrash in there sometimes hits really hard so that you either want to have it tanked or CCed. I also assume that most BC bosses will just slaughter you.

I whould love to be proven wrong and if someone has videos of shadowpriest heavy groups killing bosses (preferably BC) i really whould like to see them.

From a pvp view 5 shadowpriest might be really fun Maybe I'll try some in the lvl 49 bracket.

Bunny