I really liked the G9 a lot (as my somewhat controversial review here mentioned in January), but in the end didn't buy one because it just wasn't responsive enough.
The G10 is exciting, if only for the 28mm capability, which really does make a world of difference and the claimed 1-1.5 stop improvement in noise.
But what I really want to see, and which advertising and production claims rarely touch on and cannot substantiate, is whether the in-the-hand experience has improved: is the camera a quicker tool better suited for faster-moving professional needs?
Even if it isn't, the G10 is still a move in the right direction.
However, it is going to start to face some serious competition from the micro 4/3rds cameras. I'm prepared to boldly predict that for many of us who have a whole in our camera-hearts somewhere between 35mm and sub-pocket digicam, these machines are going to be the answer. Shaving off the ridiculous size and weight which made 4/3rds cameras functionally indistinguishable from 35mm dslrs), the micro 4/3rds machines promise a really meaningful reduction in size to carry-all-day-in-a-pocket range, but with a chip many times larger than the thumb-nail sensors in the digicam crowd.
These sensors are capable of truly excellent image quality at a wide range of ISOs. Considering that I have an 11x14 print from a 660K medium jpeg shot on the G9!! on my wall (and it gets more comments than most of my pics), I think a next-gen 4/3rds chip might well meet all my needs right up to the cusp of MF terrain.