The PS4 doesn't need much better hardware. The CPU of the PS3 is way more than it needs, the GPU could do with an update, but largely just to keep up with current features, since given that consoles are highly optimised for, you don't need the 680 or 7970 in there to produce really solid looking games built for the systems. It needs more RAM, like the industry have been saying, like we have been saying, that's what's holding it back so often. The RAM capacity of the PS3 was a stellar example of poor forethought, as was the CPU, it was too expensive. I'm still torn on the Blu-Ray drive, and probably always will be. It sold a few systems, but it cost a lot of money to do, and did it pay off? Not a lot. Yeah we couldn't have done MGS4 and a couple of other games on a single disc with uncompressed cutscenes, but was it worth the cost?
Anyway, my POINT is, I don't think the Wii U and the PS4 and 720 will have as much between them, if the Wii U is a more powerful machine than either the PS3 or 360. If they're smart the PS4 will have more RAM, a customised 450, or 550, and nothing flashy. The 360 I'm less sure about, the CPU could have an upgrade and not break the bank, and it'd benefit it, RAM could use a little upgrade and they've already settled on a GPU I hear; the 6700? Sort of the range I'm expecting. Last generation to save money, but we aren't losing a lot.