Looking over the Mastery stuff for Hunters in Cata, I'm hoping the BM Pet Damage portion gets buffed enough to make BM viable in PvE again. I believe they've already mentioned making it more suitable outside of 3's Cleave in PvP, which is fantastic. However, I'd like to keep my Skoll out all the time if I can.
That leads me to a side note. I'd also like to see more pet types have uses in PvP, rather than best/worst choices. I've always followed the mantra of play what you like and make it work somehow. Sometimes that's impossible in this game (melee Hunter) without gimping yourself too hard, but Cata is a chance to open previously unimaginable options.
Hopes? Encouragement?