It would make finding things that you don't have a clue of where to start, much easier. The disconnect for interfaces has always been that you have to know exactly what you're looking for in order to use it. With HUD, you'll be able to type in something close and it will lead you to find what you're looking for.
For those that don't like to type to find stuff... why the world are you using Linux in the first place. You need to get back on Windoze and leave Linux alone.