You can rave about Nintendo Land all you want but what is the point of making a very expensive controller a mandatory purchase for ONE GAME?
I only mentioned Nintendo Land as the example of something I'd never experienced before (asynchronous play).
Other things that I really like... art in Miiverse. I like drawing it and I like seeing it. I doubt that will catch on in PS4 as not everyone will have a Vita to draw with and it's extremely unlikely that people will draw on XBone (with Kinect or with a tablet?). I realize it's not a "game" but it's something that can be done for every game in its respective community on Miiverse.
There's also some challenges on the Rayman Legends App that make use of stylus controls. A character walks at a standard pace and the player has to control the environment to keep him traveling safely by moving obstacles, cutting ropes, stunning enemies, and so forth. I realize this kind of stuff is possible on the DS/3DS/Vita, but I think it works nicely. I also wonder what they'll do for these stages on PS360 versions of the game.
It also doesn't bother me when games use the second screen as a menu or map (as is the case in DS versions of Castlevania). I know that doesn't set the world on fire, but if it makes sense, I think it's fine.
And many people like the off TV play. I'm never fighting over the TV, so that feature hasn't come in handy for me yet.
However, Ian (and other skeptics), I can see your pessimism towards the controller. When I bought the Wii U, I didn't have high hopes for really liking the controller that much, either. I figured that the worst case scenario was that I would have paid an extra $50 or so for a dumb controller (or whatever the additional cost is), but that I'd still have the hardware I need to play Pikmin 3 and other Nintendo exclusives. As it turns out, I'm pretty happy with a lot of the things the controller adds (and I'll still get to play Pikmin 3!).