The main thing perks really comes to is balance. I'm fine with any perk, so long as there is another perk that can counter it. For example, Stopping Power is the natural counter perk for Juggernaut, and vice versa.
If there was nothing that allowed you to obtain more health, then Stopping Power would be without a counter perk, making it a threat to just about anyone. Now of course Juggernaut is not the only kind of perk to counter Stopping Power, but you get the point.
Treyarch seems to have the balance of perks down, considering the balance of perks in Call of Duty: World at War. Chances are that most of the perks will be similar to that of past Call of Duty games. Many of the perks introduced in Modern Warfare and World at War are the very basic of perks, and really cannot be without. There will probably be a few new perks here and there, but that's not something we'll no much about for the time to come.