I don't think either moving the Wii U up two years or releasing a PS4-tech competitor now would have made much of a difference. For the earlier Wii U, you might have received more PS360 ports then and now, but probably still less than even the Gamecube, which would still dry out next year as major titles moved to PS4/XBONE. And in that scenario, Nintendo would have been even less prepared with their own software. So then they would have needed to have gotten on the ball circa 2008, a time period in which the Wii was still doing gangbusters. And then you could argue that the Wii should have been PS360 equivalent, which they would have started ramping up for in 2004. Etc., etc. Basically, you're asking for them to have been a different company with a different philosophy for the last 10+ years.
On the other hand, a jump to PS4 specs now would likely have been a bigger disaster. It would have cost more, sold less, and have a negligible software differential. That could have been a console they pulled the plug on. They won't drop the Wii U, but I could see them retiring it early for whatever comes next. You can be certain that they have all their teams working on WiiU software through 2015. If the holidays go as badly as they seem poised to, in the next year Nintendo will have to map out a post-Zelda gameplan. A confounding factor is how to appease stockholders without publicly revealing long-term strategy, RE: the console wars.
I would caution, however, about being too credulous about hot air from Bethesda or whoever. I think it's been pretty clear for a while that the western players want Nintendo out of the hardware game, and they'll talk all the trash they can. As I recall, Nintendo did indeed perform unprecedented outreach to the west when designing the WiiU, and it still got them nowhere, aside from blackballed from EA.
Finally, I'm seeing a lot of poo-pooing of the gamepad. Sure, it's not revolutionary, and probably will never be (nor was the DS), but offscreen play/video streaming is fucking rad. I get a ton of use out of it. Given the choice between purchasing a game on a platform with offscreen play or full online features, I'd go for the offscreen. I think it's a major undersold strength of the WiiU, much more compelling than mini-maps, inventories, or what-have-you.