There is benefit for a small subset of applications, applications which can gain from having 3d input. Most of the stuff he does in that demonstration is not of

There is benefit for a small subset of applications, applications which can gain from having 3d input. Most of the stuff he does in that demonstration is not of this category. But interfaces like that can be very nice for architecture (or computer assisted design) and 3d data visualization (medical or other). Gaming is also bound to be an interesting application. It will be nice to see what Microsoft comes up with for natal as well. For general computing I am not sure if there is a use for this kind of interface, this stuff takes a lot of space and is long to setup while we are going the other way - towards smaller and more portable computers. Also, let us not forget that gestural interfaces are very tiresome and it would be hard to use one for a long period of time.