From what I have heard the G12 is going to add only HD video capability. I am strictly a still photographer and have the G11 so the G12 is giving me nothing that I want. The G11 is a good camera. Once I get used to it, I will probably move up to a DSLR. But right now it is fine and it takes some nice photos.
Now, I think that it is unfair to beat up Canon for not adding more features. The thing is that neither Canon nor Nikon make the sensors for their digital cameras. You can not build a new camera with cool new capabilities until you have a new more capable sensor to build it around. Right now, new sensors just are not coming out that fast.
Canon does in fact make some of the sensors for their cameras, mainly the DSLRs. They and Nikon buy the rest from Sony. Actually, some of the best sensors are in Sony DSLRs. I love the A900, 24MP full frame. But the rest of their product line is not as well developed as those of Canon and Nikon. And customer loyalty does not change overnight. So even though the sensor is amazing, they have not dominated the high end market. People buy a system, and they buy what they are used to.
Any technology company has stuff in research that's way ahead, in advanced development that's say 12-18 months out, and in production. Some of the research stuff works but is too expensive, or too far ahead, so it takes a while to move to market. When a design heads to production, a great many manufacturing details and marketing and support details have to be worked out involving a huge team of people. There is a lot more than just the silicon involved in making a new sensor. The package, the interconnect, the filters, the process, so much to work out.
Back to Point and Shoot sensors. The sweet spot of the market is around $300-400 for prosumer point and shoots. In this market, for cost reasons, their sensors have to be much smaller than full frame sensors. So you only see small incremental evolution every 3-6 months, given the fixed small size of the sensor. The latest trend is actually toward fewer pixels with less noise, and interconnect out of the light path. The pace of improvement may seem slow, but over time it's actually fairly amazing, just as with memory or microprocessor chips.
I suspect that Canon believes it has to release something new, even if it's not a quantum leap ahead, every six months. Otherwise the other competitors will catch up. So, they looked at the G11 and said, what can we add with minimal development to crank out a "new" product? HD video! Probably only a firmware change, since the camera has the same sensor and processor and lens. Still they make the new product timetable.
Well, the G12 is not out yet. Maybe they will surprise me and do a much bigger innovation. Time will tell. I suspect they will follow the pattern of the S90 to S95 evolution, with minimal investment for a new product release. Next round, hopefully will be major.