Well if Canon come up short at 37, and Nikon come out swinging with 42, with their as sharp to sharper lenses, I'll finally be moving back over.
I rented the D7000 for a video shoot this weekend, and was blown away by it. I had a cinematographer shooting the key shots on the 5D mkll, and the freedom of movement that I was afforded by the follow focus meant that the Canon's shots will be the fillers in the edit, the Nikon just knocked its sox off it with its freedom of mobility.
Canon really do seem to be lagging, it almost feels like they're ready to throw in the towel, and let Nikon return to the podium as the pros default choice. The downgrade of the G10 in the G12 was the first warning shot, and it seems that the mistakes and missteps may continue for a while.
In answer to the question - When will big billboards be out resolved by the sensors ? - the answer is they already are. This is a shot I did for Subaru last year on the P65, showing the full fame above, and a close up detail at 100%, allowing this to be printed at over twice the size of the largest billboards in the world because the huge ones use such a low DPI count, in 80-120 dpi area.
(1000 second H2/P65 - 55mm lens on a hand held gyro hanging out of a Bell Jet Ranger - yes, it was a nice way to spend four days - thank you Subaru and Dentsu!)