Depends. I feel like Cats&Dogs was the most likely pack for this to start with, and it's hard to tell how far EA would go with it - would they only do it with Pet things? Or will they do it for other EPs? Will they only do it with Stuff packs? Or will they move up to GPs?
You must remember that EA doesn't want to annoy you with lacklustre Stuff Packs that recycle a lot of code and put you off the game. It just wants as much of your money as possible as often as possible.
I think when we start getting Supernatrual packs, we'll see them merging together - which is, let's face it, pretty cool, but annoying if you only want one specific life-state. Or if we get a Horse GP, it will have Cats&Dogs-compatible items in it.
And even though we ARE paying more and EA IS being greedy, the gameplay is still so much deeper. Look at all the things even little things like hamsters can do now! Like taking off in a spaceship!
