Sony fucked up financially this gen and had some bad luck to top it off. They're going to be releasing a powerful console but it will be more affordable.
MS, I don't know. I think they will do the same as Sony, a powerful but affordable console.
Nintendo, will try to get early dominance (like PS2 and 360 did) and make sure they're powerful enough to get next gen ports.
Next gen, the consoles will be on a more level playing field hardware-wise. It's exclusives and features that will set them apart.
Sony and MS will not want to bleed tons of money like this gen. They basically had to try extend the generation to recoup what they lost.
Nintendo did very well, they're near the finish line and are gearing up for the next race.
I doubt Sony and MS will leave them for more than year on the market by themselves, so I pretty much think they will both launch in 2013.
