I just got a Canon A75 to replace my Canon S100.
The main thing I was looking for in a new camera was longer battery life, as well as faster response and at least 3.1 megapixel resolution. I also wanted one that uses CF cards which the S100 used. Most of the cameras I’ve seen use other format cards, but CF cards are the least expensive, plus I already have several 128M cards and a reader, so I wouldn’t have to buy all new cards.
I also like that it uses rechargeable AA batteries instead of a proprietary battery pack. I was getting pretty annoyed with the S100’s very short battery life. Even with a new battery it starts showing a low battery indicator after 20 shots or so. The A75 claims 500 shots on a set of NiMH batteries.