I have seen a lot of negative articles/posts about the square button on the Sony PSP. I came across the following article that says Sony fixed the problem. I did preoeder my PSP a while ago and I figured that I'd risk the chance of getting one with a bad button. This makes me extremely excited that Sony is already improving what will surely be a kick ass product.
http://psp.1up.com/do/newsStory?cId=3138532
http://psp.1up.com/do/newsStory?cId=3138532