dpreview.com lists the advances of the G10 over the G9 as:
Their review is
here.
This is correct. However, let's discuss the real-life advances.
The censor size has not increased and yet the megapixels have. What does that mean? That means more noise or rather, less tolerance to low-light shots. The test shots do not reveal this and it is quite possible that there is more noise reduction going on in-camera to compensate for the increase in MP on the standard censor size. However, noise reduction often equates to lack of sharpness.
The grip is an improvement. I ended up buying a grip and I love it. I thought it was more of a missing feature on the G9.
The wider angle pretty much makes the wide-angle lens attachment for the G9 obsolete. If I recall, the attachment, which runs about $120+/- gives you the same wide angle that the new G10 gives as standard. This is not worth me buying and ditching the G9, but it was a note worthy improvement.
The exposure compensation dial is laughable at best. Honestly, using the menus to change EV is just fine. But hey, we have to justify the price increase.
The higher capacity battery is dreamy. The current G9 battery is indeed a nice little workhorse. I often forget to charge mine and I get away with murder as far as using it. The extra mAh should offer quite a bit more shots in RAW or JPEG.
The rest is just laughable again.
I think the G9 is a great buy. The current wide/zoom is passable and what you cannot get you can zoom or go wide with your feet or spend $300 on the zoom/wide adaptors.