Some real good points there buddy.
I do agree the Xbox 720 will sell a lot better than the Xbox 360 did, but I also think the PS4 will sell more next gen. The PS4 may lose a couple key selling points that the PS3 had such as free online and internet browsing, but it's a pretty safe bet that the PS4 will launch at a much more reasonable price point than the PS3...and hopefully with some good launch titles (maybe Gran Turismo 6, LBP3 or something similar).
I also agree the Wii U will sell WAY less than the Wii. I don't see it completely flopping like the Gamecube, but I can see it selling pretty similar to the SNES (50 millionish lifetime). It'll be more expensive than the Wii (no way in fuck it launches at $250) and as you pointed out, it won't have the motion control gimmick/curiosity.
I can't make sales predictions without knowing what the launch prices and launch games will be, but I'm thinkin the PS4 could be Sony's return to the 100 million club if done right, and the 720 should have increased sales.