Have a look in
http://www.dpreview.net/forums/forum.asp?forum=1010 . This is the Canon forum in DPReview. Lots of info on the G3 from new owners. Seems most who have gone from G2 to G3 are pleased although some G2 owners are still happy with what they have.
For ASFKAP try this for the comparison between the Canon G3 and the S45.
http://www.dpreview.com/reviews/compare_post.asp
The G3 looks to have a fair bit more features than the S45 but there is a difference in portability in the S45's favour if that is a factor. There are so many very capable cameras available, each with their faithful/rabid proponents. Some of the DPReview forums become very partisan.
