We first saw the Hydra, then called the Sixense (after the company that originally developed it) back at CES 2010 almost a year and a half ago. I was impressed with it then, as it felt more natural and responsive than a Wiimote (what doesn’t now?), and used a genuinely different and powerful technology. It’s based on magnetic detection of the controller, instead of optical, and it felt great then, though they had some work to do on latency. It seems like they’ve finished polishing it off, because it’s headed our way in June.
It’ll detect position and rotation quite accurately, and each Wii Nunchuk-like controller has an analog stick and four buttons.
The Hydra controller will be open for pre-orders in May, and it comes in a special Portal 2 bundle; they actually worked with Valve to make this thing work extra well with Portal 2, and have done so (they told me back in the day) with a number of other big games and developers. It says 125 games are compatible out of the box, and they’re listed here.
The Portal 2 Bundle includes the game, the Hydra (base and two controllers), and some special DLC levels, and will set you back $140; no word on the non-bundle version, but I’d guess it’ll cost around $90 or $100. There’s more information at the Hydra minisite.