I for one can't wait for road disc brakes.
I have worn through rims on my mountain-bike and commuter-bike due to wear from rim brakes, resulting in blown tires and I was once close to having my leg pierced by the sharp edge of the rim pointing out when that happened. Now both of them are disc brake equipped.
As for stopping power, I have not tried disc brakes that were as powerful as rim brakes - at least not in the dry. Possibly this could be because of lack of experience, since I haven't tried a proper lightweight road bike with high end disc brakes. But the best brakes I have experienced, was on my Cervelo Soloist Carbon with Dura Ace 7800 on Fulcrum 1 wheels. I was able to break in the manner eric described, where the rear wheel lifted just a little bit. Because of the sheer thrill of the G-forces, I would actually do this as often as possible.
I also suffer from squeaking from the disc brakes. Whether in the city or the forest, people look very annoyed at you when your brakes squeal. For this alone, it would be worth the premium for the Kettle carbon rotors if the were virtually quiet during breaking, which I would expect them to be?!
Despite these complaints, I STILL want disc brakes for my road bike. I just like the idea that I'm not grinding away on my rims every time I break. I like that they work in the wet. I like that my wheels will not get dirty from break pad residuals. And I love that they are always perfectly adjusted.
I'm contemplating on getting a Specialized Crux Pro Carbon Disc as my road bike, even though it is a cross frame. Since my main target is a comfortable ride, I think it will do the trick. The Cervelo beat me up, so I got a little weary of it, but that might partly have been because the frame was too small for me (56 cm frame, I'm 184 cm). With the red Kettle rotors, I think it would look like a proper racing bike, and not like a commuter bike.
I'm just waiting for Shimano to bring out Dura Ace hydraulic brakes and a proper 1x11 road gearing setup like the SRAM XX1 - another thing that came from mountain biking which I think is brilliant. Hopefully summer is not over when this happens - we still have a little bit of snow here in Denmark so for now I can wait.