People kind of expect it though. The market is sort of stuck in it. The general consumer expects a bunch of movies to come out in the summer, a bunch of games and toys during winter, and a bunch of school supply sales during August and September. I personally don't really get ANY games during pretty much any time of the year even though I want to, because I'm usually broke, but Christmas and sales are a perfect reason to splurge. I'm not sure a lot of people are like that, but it's something else to consider.
Seeing some sort market data on this would be kind of cool. I know there's a few huge games that have released at random times in the year.