BanjoKazooie

The PS3 was "supposed" to be more poweful, but actually, the Xbox 360 is more powerful.  The PS3 Cell is gimped, the GPU cannot even close to keep up and the RAM is a problem.   The only thing the PS3 had that was better was the blu-ray drive.  Even now, games like Ninja Gaiden had to seriously cut back on the number of enemies and polygons on screen - not a little - TONS.  And the PS3 version of Dawnguard DLC for Skyrim is embattled due to the PS3 not beign able to handle the graphics.  Expect the graphics to be seriously downgraded by the time the DLC becomes available on Sony's system.

The 360 had a very smart online structure from the get-go, had a built in upscaling chip, and many things about it that just made it a serious next gen console and the most powerful without being overly complex.  It was simply very well thought out.  sure, it had heat issues.  but the console's capabilities were astounding.  

It was and is simply an amazing console.

That is why it did so well and that is why is stomped the PS3. It is simply superior hardware compared to the PS3.  People can talk about theoretical (read: make believe or hoped for) specs, but in reality, the Xbox 360 CPU outperforms the gimped Cell in the PS3. this is observable and consistently repeatable..  And the GPU is far better than what Sony put into their system.

the Wii's success was built upon perfect market timing.  the world was "ready" for a casual gaming system and the smartphone market captialized after the Wii proved that market viable.

Now, people have been saturated with that and want the real goods once again.  that's where the Wii U comes in with its powerful hardware, very well thought out online system, Blu-ray derived storage, social interaction, etc.  Basically, everything the Xbox 360 did right, Nintendo is doing this generation and then some.