First of all, I don't believe Nintendo's focus here is to make a typical "controller". Nintendo hasn't abandoned the idea of bringing gaming to everyone, they're not reversing the Blue Ocean strategy and making a "GameCube 2" here.
My bet is that the controller that's beeing talked about here is a smartcontroller, a controller with a lot of stand-alone functionality. It might even have universal remote functionality, both for IR and BT devices. Part of the design philosophy behind the Wii Remote was to make a controller that looked more like a TV remote and less like a game controller to avoid alienation towards non-gamers. You shouldn't be ashamed to have it on your coffee table, to pick it up and play games when people come over. Well, it's time to go outside, to meet people where people are. Bring your controller from the coffee table, and to the café. Project Café.
The new controller will not just be a screen to stream content to from your home console, it'll have built-in software, wi-fi technology for "streetpass" and other notification and messaging functionality, apps, maybe even full support for Virtual Console. Bring it with you wherever you go, make it a part of your daily life.