Good idea; very useful feature. If I recall correctly, Keith Code teaches rapid, throttle-blipping clutchless downshifting as the way to go, but says it's one of the most complicated techniques to execute properly, since you're turning, braking, and blipping all with the same hand. There's a reason why every SBK and MotoGP team uses auto-blippers these days - frees up some mental/physical bandwidth to use for other things.
Do you need automatic rev-matching for downshifts? Not really, and of course some will say you really don't need a quickshifter or a slipper clutch either if you have good technique. There's some truth in that, as well as some pleasure in getting it right without aids. But if you think QS and slippers are good things you'll likely think this is a good thing too. My guess is all sportsbikes will probably have them before it's all said and done. Heck even Nissan 370Z's and the new C7 Corvette have it.
@WAfatboy - the Proshift actually rotates the shift drum itelf; all you have to do is hit the shift button on the handlebar, a bit like a mountain bike shifter if you've ever seen one. Don't even need a foot lever. The rev matching does work similarly, though.
