What you neglect to realize is the fact that Sony is constantly reducing the manufacturing costs of the console, the 40GB model is now fairly competitively priced with the 360, and the PS2 and it's games continue to outsell every other console on the market, including the Wii, by a large margin. And given some of their biggest titles are hitting the streets this year, you'll likely see the PS3 picking up a lot of speed.
Sony aren't going anywhere, and given how successful the PSP has been in reality, I expect they will make a PSP2, and for all we know, it could surprise us all and start being a real threat to Nintendo. People can say I'm crazy, but I don't think anyone who looked at the performance of the Xbox would have ever expected the 360's relative success. But Microsoft did get a foothold, just as Sony has in the handheld market.