|Things are going to feel a little different.|
It is certainly an exciting technology but certainly nothing new. As early as 2008, the i.Tech Virtual Keyboard was already being sold at Amazon.com. The latest projection keyboard to come out in the market is the Celluon Magic Cube Laser Projection Keyboard and Touchpad. It debuted with an SRP of about $200 during the summer and is fast gaining the interest of tech aficionados. And what's not to drool over? You're typing with laser!
While projection keyboards are certainly a step closer towards realizing a Matrix-like future, personally I would wait for the second or third generations of this technology to come out. As were most transitional technologies (i.e. laser discs, zip drives, etc.) it won't take long for the trend to snowball into better, faster and cheaper versions of the product.
At any rate, apart from the flexibility of using your projection keyboard with multiple devices (from PCs to mobile gadgets) the clear upside for the device -- you won't have to worry about spilling your drink on your keyboard!
Learn more about the laser guided keyboard here and here (Death of the Keyboard).