I dont really see what the problem is. The PS3 games keep looking better every year, and with the addition of the Move, Playstation Plus, and various other features Sony is adding, it seems to me like the PS3 is still picking up momentum. There isn't much of a reason to try to hurry up and push out new hardware on something that is still growing.
IMO the Wii is the only one that is a bit limited with growth, unless it has a hardware change. The Wii is perhaps a good console, and fun to play, it has software to support it to make it great. The software is what is really keeping the Wii ahead, the hardware and attachments are sitting still for the most part.
Xbox is similar to PS3, its also a growing console because of its network support and Kinect release, therefore also doesn't have much of a need for a hardware upgrade at the moment. The only problem, if they don't use digital distribution games like FF13 are going to come out and need multiple discs, but I guess that's not such a big deal anyway.....
