Thanks for the analysis.
I would like to add this observation:
We really dont know yet what kind CPU will be in the final retail version of the WiiU.
Dev kits could have used modified 360 CPUs for all we know.
Also, I found it interesting that IBM was more forthcoming about their CPU than AMD was about their GPU during E3. Did that mean the CPU was ready before the GPU? Did it mean the CPU will have more of a significant role to play than normal? Or did it mean that Nintendo was more concerned about spilling info about the GPU than the CPU?
My guess is that the CPU was probably ready before the GPU, but I'd say that the difference was mainly due to the corporate culture of the two companies. AMD tends to reveal very little about their products until they're very close to being on shelves. IBM, by contrast, publishes very detailed information on most of their hardware before it's even released, and they even have their own journal for that very purpose (which, incidentally, is a great repository for anyone looking to speculate further about the Wii U's CPU, as it shows what sort of tech IBM have developed that could go into it).
OK... but what's in it for EPIC? Surely they make more money getting as many licensees as possible... and covering more formats is one way to achieve this.
Additionally, porting from UE4 to UE3 is likely to be a LOT less hassle than it would be to take a current 360 or PS3 game and port it to Wii. Sure it's work but you won't have to completely chnage all your assets and art....
Epic's best interest is to have their engine available on as many platforms as possible, which is why I believe they will eventually announce it for Wii U. They also have an interest in the next generation of consoles being as powerful as possible, though, as that will both increase the sales of UE4 to developers, and also increase the amount they can charge for the engine.