IMHO the ps3 is really a glorified blu-ray player. Sony rushed the release to push the numbers of blu-ray players sold to aid in their marketing campain for that HD format.
From what I have read the ps3 is not meeting any of the sales goals, and is actually being out sold by xbox360 and wii by more than 2 to 1. which is quite surprising considering that they were the market leader with the previous generation consoles.
I don't think that the xbox360, or the wii will be going away any time soon. As indy007 stated the 360 has another couple of years before the next gen xbox is released, and the wii seems to have captured a large market segment with a gaming console that is really inovative in it's aproach to playing games but really low tech in it's hardware compared to the 360, and ps3.
Truthfuly I will never buy another Sony product, and this coming from someone that was a diehard Sony man. Sony has gotten to big, and to powerful, and their products aren't all that great any more. They worry more about protecting their movies, and music than they do about building good electronics.