R&D Talk: DSLRs with touch-screen displays?

The iPhone with its touch-screen, as you all know, is extremely popular. So far, the compact digital cameras with touch-screens have had their niche fanbase, but they haven't "broken out" among general-consumers or the mythical average photographer. But, what about DSLRs with touch-screen displays asks Chris Gampat at Photography Bay? What benefits and what issues would they bring up?