I guess it's official now even though none of the camera review websites have yet published the news:
1. Canon seems to be stretching the G-series this time, not adding anything really significant over G11. (Significant in this case refers to larger sensor / ultrawide lens / smaller form factor / faster lens / more tele / evf / filter threads.)
2. Times have changed since the launch of G10 and G11. M4/3 seems to be competing directly with the G-series and Olympus EPL-1 is not only about the same size, it is almost the same price now. If I were to spend $500 on a serious compact, I wouldn't think twice about getting the EPL-1 instead, which is in a different league all together. As far as fixed lens compacts go, S95 (smaller size and $100 less than G12) appeals to me more.
3. Nikon has complicated the equation by launching P7000 for the same price and roughly the same form factor. P7000 looks promising and many have already raved about its IQ. Panasonic Lumix LX5 (also priced at $500) launched a little earlier is also getting rave reviews. The G12 will have to be 'really special' to compete with P7000, LX5 and EPL-1.