In one of the Iwata asks, Satoru stated how they do extensive tests, running HW for thousands of hours! Judging by how badly unoptimized the OS was, its clear Nintendo was not ready to release Wii U, but had their mind set on holiday '12. Its very possible, even probable, that Nintendo underclocked Wii U to be on the safe side, to just receive current gen ports while it enjoys the "headstart", as it continues to do more hardware tests. Obviously, there is plenty of room as far as power consumption goes, 75w max (current 33w usage).
A modest bump on the cpu and gpu are believable and I do expect it to be unlocked (along with more ram) in the future. I doublt the intent is to dupe competition , but its Nintendo being more on the safe side as they do more tests to get the final lock down on specs. Lastly, Iwata recently stated that he has to convince devs that the console is not underpowered. Iwata directly addressing the power issue, as if disputing it, lends credence to a possible HW update via firmware.