Gamestop lowering their used prices is not going to do anything productive. If this goes nationwide I can't think of any win-win situation for them. More than half of their profits come from the huge margins they set for buying and selling used games, and that profit is continuing to rise. All the while the profits earned from new games are slowly falling. Best Buy on the other hand is a huge retailer that earns most of it's money with consumer electronics, major appliances, car equipment, movies, and the various maintenance, repair, and installation services they provide (at absurd costs). They can easily afford to get into a price war with Gamestop, because they can meet and beat pretty much any offer Gamestop can possibly make. Sure it'll come at a loss to Best Buy's video game income, but when it's such a small percentage of your net income, it's well worth the cost of potentially cutting into your opponent's business, or even killing them off entirely. This comes right out of the Big Box Retailer vs Specialty Store playbook, and for the first time I'm rooting for the big box. It's also good for publishers as buying a new game even at used prices is still a sale for them, and it supports the industry. Whereas buying a used game at Gamestop is just filling the coffers of a company filled with assholes and bad policies.
I'm sorry I can't consider Gamestop a specialty store dedicated to gaming enthusiasts when I come in to buy a new game and they tell me they don't carry it because it wasn't going to sell 10 million copies. If a store that specializes in GAMES tells me they don't carry a GAME, then they're no different from the casual game sections at Target, Best Buy, or Walmart, complete with the incompetent staff. In that case what's the point of them existing? At least Gamecrazy tends to have some knowledgeable and helpful people, a wider selection, better used prices, and will sometimes let you try out a used game on one of the TVs before you decide on buying it. I swear I've got 12 Gamestops within 10 minutes driving distance and there's not one brain among them.

em, the evil empire has my vote this time.
*Prays for nation-wide offer*