Personally stopping second hand games will kill the industry. Fact: If I hadn't been able to pick up Assassins Creed then I can guarantee you I wouldn't have bought any other AC games. There are some titles that I can't validate paying more than $10-$15 for because I have no clue if I'll like the game or not.
I would be ok with the limited number of 2nd hand users option, so long as the price reflected it. As in: 5 trades left $25, 3 trades left $15, none $10. I also feel that they need to put more games out on digital download, but that's only worth it for me if there's a price difference and if it's put out the same day as the retail game.