While we've never had a full-color screen in our hands with a console, we have had displays in our hands before, with the Dreamcast. I would consider it a bit of a warning that the Dreamcast's promises of how the display would be useful almost entirely failed to pan out. I think the core problem is that on average, you're not going to split your attention between two screens, if for no other reason than physically acquiring a screen with your eyes is a significant fraction of a second. The fraction of a second spent changing screens better have a really good payoff.

For every use case given for the auxiliary screen, I'd ask, could it have been done on the Dreamcast (even if not quite as well), and if so, why didn't it work there and why will it work on the WiiU? Merely saying "now it's in color" really isn't good enough, I think.

I can generate hypothetical uses as much as the next guy ("call plays in sports games!" "multiplayer shooters!" "rear-view windows!"), but once I tone down the excitement (easy after years of practice) and really think about the pragmatic issues of trying to use this auxiliary screen, I'm not actually coming up with many situations in which the auxiliary screen is the best solution, which is the real criterion to measure uses of it by, as opposed to a solution. Play calling works, but that's an awfully elaborate screen for such a use case. Rear-view displays don't work at all. Locally multiplayer shooters are OK, but what will the main screen be doing?

An example in the current generation: Light gun games are best with motion controllers (haven't tried Move but assume it will be at least as good as the Wii), because that game style really uses the controls, a two-dimensional high-speed directional input system that can harness muscle memory; with only a little practice I can flick reliably from one side of the screen to another and it isn't long before there is no longer any barrier between where I am thinking the reticle should be, and where my muscles are putting it. I have never had such fun with this genre as I have on the Wii. Motion controls are not merely a solution, but are the best solution, beating out even "badly-calibrated arcade gun without on-screen reticle". Whereas "wiggle the stick to attack" is not an argument in favor of motion controls, because while it is a solution, it is not the best solution, and the Wii's reputation has suffered from the number of games that have tacked this on so they can claim "motion control". Motion control as a whole has had a big problem with being a solution instead of the best solution. Given the price of the screen here, both in dollars and in controller comfort, I don't see it being the best solution to enough problems to make it worth it.

(Opinion calibration: I was actually up on the Wii, precisely because motion control really did open a lot of things up, and I consider it still underused. Unfortunately, sophisticated uses rapidly become very complicated AI problems to try to figure out what it is you actually meant. I'm also at least modestly up on the 3DS' long term potential, but it's going to take probably 2 full game generations before the developers themselves get over seeing it as a gimmick and start "truly" developing for it. I don't consider myself a reflexive naysayer. I really do think this isn't very likely to turn out to be useful for games, though. But I could be wrong; this could be the iPad of the space. Who knows.)