You can imagine there are a lot of people trying to find a way to converts us RPG'ers into steady customers. I'll buy the PHB and the DMG and probably just a few other books. I'm sure 90% or more of the people who play D&D are just like me. They would love a way to get more of my money, yet the problem is I don't need any more of their product. My DM purchases most of the other interesting books and I can use anything I want from them. What I can see happening in 4th edition is perhaps the core rules allow you to build a basic character, and the only way to "accesorize" the character would be with the use of collectible cards. I'd buy a pack of cards containing feats, spells, magic items, etc, and use them to flesh out my character. WoTC would find a way to make it work. They might even make it so compelling that I'd even like that kind of system.