EA already did this with Battlefield Bad Company 2. You only get to access the "VIP" content if you have the code that came with the original disk. You can at least play the basic maps though.
It does however, affect the rental market too - not just second hand. I use LoveFilm for my XBox games and it works out a lot cheaper than buying a game you will only ever play to completion once. If however this kind of VIP content becomes all to common, it's going to make renting games pretty pointless.