360 isn't going anywhere. Not only does it have a year lead over the PS3, it has Microsoft backing it. The PS3 will no doubt do better in Japan than the 360, but in North America, I think the 360 will keep its lead for a while. Price is always a factor, I don't care what anyone says, thats helping the 360. More game selection, thats also helping.
The 360's hardware is also older, meaning it will become cheaper to manufacture sooner than the PS3.
I've read that the PS3 is losing $250 a unit. If thats even close to the truth, I highly doubt Sony wants to sell millions of units anytime soon. If they are smart, they would supply small amounts, keeping the general hype around the system alive, until they can afford to turn a profit on them.
Either way, if PS3's come into full supply in the Spring, and MS drops the price of the 360 to lets say $350, and add a bundle that includes the HD DVD add on drive for $500, maybe even throw in a game, how many potential PS3's buyers do you think would jump on such a deal?
Both systems are next gen. Both offer high resolution output. Both are going to battle each other UNTIL the next next gen systems release in 5 years or whatever. Anyone that thinks that one of the companies will "lose" this battle, is oblivious. Neither company can afford to just "lose", both will be around, enough said.
With that said, I hope the PS3 availability increases so I can buy one. I am a gamer, I will have all three systems (360, PS3, Wii) and a PC.