The S120 is too big. Size and shape wise, my Elph 500HS is just perfect. The rounded and beveled corners really make a difference as far as comfort in your pocket goes. Now, if I could get an S120, even with a 1/1.7" sensor in that size and shape, that would be something I'd buy.
I agree but I don't agree. For some occasions, I have found the S95 to be the most useful pocket camera I have ever owned. It was marvelous in Paris...simply marvelous. We also own an ELPH 300HS, which, as you describe with the 500HS, has rounded edges. The 300 is even more pocketable than the S95 (as I recall it is also smaller than the 500), but there is no question that the S95's images are generally (but sometimes only slightly) superior. It is amazing how well the 300 fits in a pants pocket; in my mind it is more pocketable than an iPhone 5s in a case.
I now own an 'M' as well, and with the 22mm pancake attached it is (if you're motivated) pocketable as well...and even with its flaws there is no question that the M produces images superior to the S95.
So I would love to get my hands on the '1-inch sensor' S; if Canon produces it in the general image of the S-series (and somehow it acts more like a DSLR than a point-and-shoot, in terms of its responsiveness), I will probably buy it.