Well, there's always the possibility of Move selling extremely well, 3D gaming being a big hit, and charging for premium services, similar to Xbox Live. The 360 would still make huge losses if they didn't have the revenues of Xbox Live. Last time I checked, they made like 2 billion dollars already. PSN barely did 200 million. The numbers could be a bit old, though.
There's just no question if there will be PS4. The real question is, how it will be. Will they do the same as the PS3, so subsidized, but not as bad as the PS3, or will they go "the Wii way" something compeletely different, new controller scheme or something completely else.
updated: 14.01.2012
playing right now: Xenoblade Chronicles
Hype-o-meter, from least to most hyped: the Last Story, Twisted Metal, Mass Effect 3, Final Fantasy XIII-2, Final Fantasy Versus XIII, Playstation ViTA
bet with Mordred11 that Rage will look better on Xbox 360.