My first impressions: it's small (much more so than the Canon compacts I've had) and feels satisfyingly hefty (the body is mostly metal, rather than the plastic used in the A570). The lack of proper manual control (there's no shutter/aperture priority and, perhaps less importantly, no manual focus) could take some time to get used to. I've yet to test it in a gig situation, though the dynamic range still seems a bit low compared to my old G2. (How it compares to Canon's higher-pixel-density non-Super CCDs remains to be determined.)
The camera also has about 25Mb of internal memory, which it can use to store photos in the absence of a SD/xD card. This is only accessible using PTP. (There is a Linux FUSE filesystem for PTP named gphotofs, though for some reason this wasn't working on my (Debian) server (though it did work on Ubuntu)). The camera has a function to copy photos between the internal memory and memory card, and photos get renumbered to fit. This appears to be acceptable.