It has its uses, but I feel like we've already seen them with the Dreamcast VMU and the Gamecube-GBA link. Neat for a few things, but nothing mindblowing. I don't think making the screen larger and a touch screen is a colossal step up. Hell, the Wii and DS are linkable, and what's that been good for? You can download demos and I think some Pokemon game used it. There is also Remote Play for PS3/PSP, but only a few games use it, and I don't know of any games that make any use of PS3-PSP connectivity in any other way.
If the system comes with both a Wii-style controller and one of these, which is basically a Classic Controller with a big touch screen, I won't mind. Each can have its place. What I would mind is if this is the sole standard controller, and controller-screen functionality is shoehorned into every game.