Mindful also of the age of the 21mpx FF sensor, I'm of the view that the 18mpx FF sensor will be pushed into a cheaper body, but also that some photographers are also very keen to see a higher pixel count. My current view is as follows...
1Dx - FF 18mpx Sports and photojournalist
5DIII - FF 35-40mpx studio / landscape camera - 2013 launch perhaps
7DII - APS-C 28-32mpx top end crop - 2013 launch perhaps
9D - FF entry level 18mpx - helps keep cost of 1Dx sensor down - early 2012 launch
70D - APS-C 28-32mpx prosmer small body - 2 year cycle 2012 launch
650D - APS-C stick with current 18mpx crop sensor, pushing up a few mpx with the 700D and so on
1100D as is now, 1200D drops on whichever sensor canon deems cheap to manufacture, 15mpx, perhaps even 18mpx
G1x APS-C mirror less solution using EF-S lenses - 2012 perhaps
G100x compact mirror less solution using bespoke EF-G lenses, 1/1.6" perhaps ? - 2013 perhaps
G1000x compact mirror less solution using fixed zoom lens
Partner with a phone manufacturer for Canon lens/sensor on a phone - 2012/2013 ?
I'm not sure if Canon could push the APS-C sensor to 28-32MP for two reasons:
1) The Sony APS-C sensor is already struggling with high ISO noise at 24MP and it's slightly larger
2) In marketing terms what would a 28-32MP sensor say about the 18MP sensor in the 1D X?
I think that sticking at 18MP but improving the noise performance and dynamic range might be a better option (and would fit better with Canon's current 'quality not quantity' megapixel marketing message). Whether this will happen or not is another question; it might depend on how much traction the A77 gets and what Canon think that Nikon will do with the D400.
I like your ideas with regard to the compact camera lineup, but I think that the 'G1X' name is a bit too close to Panasonic's GX1! As for your idea about Canon partnering with a 'phone manufacturer -spot on... In fact, I'd go further: they should buy a 'phone manufacturer.