Acoustical modeling to determine the point of origin of sounds is nothing new, and although it's a wonderful idea to implement it as they are here, it'll go to hell the moment there are other vibrations on the surface. A low-pass filter should stop most environmental noise bouncing off the table/surface from triggering it, but if you put down your coffee mug on your desk, or bump your leg to the table, you'll likely get false input. Not to mention, as others have pointed out, the processing costs. This could be another of those technologies which is great for allowing input on an inert and durable psuedo-sterile and wipe-clean surface in a quiet, controlled room, but likely won't be worth much outside of bizarre use cases like that. But it's still amazing research.

At this point, I'm hoping that the system becomes so deadlocked with Software patents and everybody has a sword to everybody else's throat that even the big players have a reason to try and get the system dismantled. I'll be like a fever: unfortunate as it happens, but useful for ending the infection.