I think the idea of what they're trying to do, controllers that are detectable in 3D space, is a great idea. We've seen great success with the Wiimote for such things, and even the PS4 has done pretty well on that front.
However, I'm really not certain they're doing it properly. In general, the controller looks ridiculous, and has a severe lack of any sort of input control. Two joysticks, four face buttons, and two triggers? In this more modern age of gaming, that just doesn't feel adequate when you have peripherals like a HOTAS, the present day controllers on consoles, or even a mouse and keyboard. Games will have to be designed specifically with that controller in mind, and a great deal of actions are going to have to be mapped to motions for it to work, and the motions are going to have to be really, really tight and clean so that the user doesn't accidentally fumble it.
If they did something closer to the way the Wiimote works now, with it's various selection of easy-to-reach buttons, I think it would be a lot easier to adapt the controller to games that already work now, rather than only functioning with games that will be released in the future, with the Rift in mind.