If I like the series, or the premise of the game, if I like and trust the developers, and if I think it'll be worth paying a full $60 for (I'm not a very wealthy person), then I'll pre-order. I get a nice little bonus, and the assurance that the game is there. I did it with Catherine (for the free swank), doing if for Battlefield 3 (might be out of stock), and I'm going to do it for Mass Effect 3, Aliens Colonial Marines, and Far Cry 3 all because I like those franchises and think the games are looking pretty good. Coming from a guy who will usually wait a year for a game to inevitably drop down at least half of its original price, a pre-order means I expect high things from them.