WotC are doing a fine job milking it for all of its worth. First it was 3.0 which was fine and dandy. They released a bunch of books on it, which I bought, most of them. Than they released rule set 3.5 and all of the new rules books, etc, which I never bothered to buy. Now 4.0? I'll just go back to AD&D and find some of the old resources in used book stores.