Mobile phones are powerful enough to match PS2, maybe even the original Xbox in terms of power. Only problem is that touchscreens are a horrible control scheme, and no developer is going to spend millions of dollars to bring over modern games when the only way they would sell is free-to-play or for $5 max. Square Enix ports over older games, but most of them are over $10 and can't come close to matching the huge revenue that their F2P games have.

Seeing as how mobile devices have been running one of the Xbox's best-looking games, KotOR, for almost a year now at resolutions more than four times what the Xbox was capable of, I think they might be a teeny bit more powerful than the Xbox.

One thing that mobile and console gaming have in common: Graphics are not the problem.

In the end they really are going to scale it for mobiles and not WiiU.

KotOR was super optimized for mobile when it was ported, and relatively forgiving in the graphics department. You won't see games like Halo 2 or Ninja Gaiden Black any time on mobile soon, they are just too demanding, even if they tried to optimize. 

Quoted for truth ^_^  I really wish developers would think outside of the box. On screen buttons and tapping are not the only ways to control touch screens. I think there is a lot of room for depth on mobile platforms should more developers make that leap.  

The first image is Halo 2 on Xbox. It has 307,200 pixels.

The second image is NOVA 3 on iPad. It has 3,145,728 pixels (that's a full order of magnitude more). It also has vastly more detailed textures because it can access more than ten times the memory, and more extensive use of shaders and lighting thanks to a much more modern GPU architecture.

Graphics are not the problem. You were much closer to the mark when you were complaining about mobile's interaction and business models.

Nova 3 is slow and buggy as hell. The game has no substance at all.
It's beautiful eye-candy, but that's it. You have to consider things like AI, landscape scale, etc, not just graphics when it comes to power. Going by that logic, Infinity Blade would be the pinnacle of power, and it's not. 

So when you say the word "power," what you really mean is "man-hours of design and programmer work?" Because nobody is going to think that's what you're talking about when you say "power."

By "power", I mean the hardware's ability to perform tasks in the game that result in the wholeness of the game. Power =/= graphics. What's the point of that great resolution output and textures when the game is severely limited in terms of enemy A.I, world design, and tasking? In games like Halo 2, you could have 50+ enemies on the screen, each doing their own thing, in a map that is probably bigger than all of Nova 3. Some games have tried and come close to the quality of Xbox and PS2 games (Ravensword is one of them), but small things like huge load times due to being able to display only a small part of the world at a time hold them back. 

In that case, you're just full of it.

Apple's A7 chip benchmarks in the ballpark of a dual core Sandy Bridge i5 from 2011.

The Xbox CPU was a P3-based celeron processor from circa 2000. That's what, six generations of Intel behind?

You want to talk about memory bandwidth? Xbox has a theoretical 6.4 GB/s, the same as an A5 SoC two mobile generations ago.

The flash-based storage in a mobile device will stream data faster than any optical drive I know of, and far faster than the DVD drive that shipped in the xbox.

Even with the "bare metal" advantage, there is no meaningful metric by which the Xbox outperforms current mobile hardware. The 50 enemies and large game worlds that get you so excited are feats of software engineering, not hardware muscle. They are possible because game designers decided to spend their processor and memory budget on more characters and a larger game world rather than high-rez textures. The limiting factor is development resources, not any kind of compute "power."