Sony isn't doing too well generally due to large competition in the electronic market.
Usually, next-gen consoles from Microsoft and Sony won't generate a lot of profit in the beginning(X-Box being a good example). Thanks to high-end performance chips and expensive hardware, both companies will have a tough time to produce a lot of the next-gen machines and getting actual profit.
Nintendo, believe it or not, is most likely to gain profit before Microsoft or Sony does. Heck, take a look at the handheld market right now. DS is beating the PSP, not just because of games like Nintendogs, but because it's profitable. PSP is too expensive to make, making Sony to lose out regardless if the system is doing well or not.
That's why console companies are more interested in gaming sales than hardware sales. DS is one that's not doing too well in game sales, yet it's selling well with the hardware.
Because the Revolution is powered by DVD format(rather than the new expensive HD-DVD or BluRay) and not-so-expensive hardware parts(not as powerful as the PS3 though), it'll be cheaper to produce(unlike the 360 and PS3) and have a much lower price point than the other two consoles.
Hopefully next year, Nintendo will show us some impressive tech demos in E3 or they're gonna lose out in the market.