One of the biggest necessary evils of a touchscreen is a lack of tactile response.
I personally don't think it's as big a deal as most make it. LIke all the blackberry users that laughed at the iPhone when it first came out. Most are using full screen android or iPhones now.
Full physical keyboards are more efficient than touch screen keyboards, but I don't think this new tech will prove to be near as efficient as a full physical keyboard. Most people will probably be just as good or better off without it.