PC Pro has an interview with Mark Shuttleworth, who has redesigned the interface on your computer for the Ubuntu operating system. In it, he says:
“One of the first things people do [when they get a new piece of software] is go through all the menus. They almost memorise and scan all the menus, and are getting a feel for what’s there. The challenge is for less-experienced users. They’re essentially having to rescan all the time to find what they want.”
I'm not sure this is accurate, and I certainly don't think it'll work without some good artificial intelligence to understand what we really want, much like voice control and gestures on the TV. If you are simply learning a bunch of text commands, this is a very backwards step, heading closer to the old fashioned command line interface. It is quicker to complete tasks that you know well, but very hard to learn what to type in the first place.
The main problem that is targeted by this design is discovery. Shuttleworth thinks that this approach will aid discovery and that might be true if you know roughly what you want the application to do, but what if it has hidden features? You might lose out on so much because it just doesn't occur to you. "Less-experienced users" might actually find it easier to have hints in the menus, rather than having to guess.