I don't think you need buttons, for some things maybe but in general no. its just a type of interface. here is a argument against natal and touch screens though I cant remember were I got it I think it was on wiki.
Conversely, while arguing against the lack of physical contact in touch screen phones, PC Magazine's Sascha Segan argued in February 2009, "This is one of the reasons why we don't yet have the famous Minority Report information interface. In that movie, Tom Cruise donned special gloves to interact with an awesome PC interface where you literally grab windows and toss them around the screen. But that interface is impractical without the proper feedback—without actually being able to feel where the edges of the windows are.
correct me if I am wrong
stop me if I am bias
I love a good civilised debate (but only if we can learn something).
