Reading the latest info about WOTLK on wowinsider, it looks hunters and their pets will see quite a few changes. The talent trees will be different, as in that the Beastmaster now really will be a ‘beastmaster‘ who’s pet will have extra abilities etc.
And different pets will have different abilities based on their ‘pet familiy‘. Not sure how I feel about that, my hunter has two nice lvl 70 pets, and I certainly don’t feel much like leveling another one up. I hope Northend will have a few new nice pets, and that we will get an extra slot for one of the new pets, so I don’t have to abandon one !
http://www.wowinsider.com/2008/07/21/hunter-pets-to-have-family-skills/
http://www.wowinsider.com/2008/07/24/clarification-on-pet-talents/