could make a fine replacement for an SLR during the times you don't want to carry as much kit.
I agree on that, and that's one of the reasons I am considering buying one when it gets released and tested by dpreview.com and/or others.
But, I also found, after trying my friend's G10, that to many, including me, it is also a goor replacement for a compact camera. It is small enough to fit in most bags, glove compartments, etc, and Canon makes a simple belt leather case for it, just like for my current Ixus 950IS; in the end, that's how I always carry it when travelling.
Clearly, this is highly subjective. In any case, my two-year-old Ixus 950IS, which I liked overall, is on sale on ebay.