Stone, Canon needs to supply 'us' because if they didn't then we'd be using Nikon, Sony or maybe Leica. Canon wants the cache of being the pro choice even though we may not be the largest market segment. By our patronage we prove Canon is THE brand, the one that everyone else should desire.
I can't tell you how many of my shoots these days have B-roll crews, filming me working for such and such magazine/product/advertiser website, so a lot of people get to see what is in my hands. Beyond that I seriously get asked 'What camera should I/my wife/son/daughter/granny get?' ten times a week, and I always say Canon. I think I alone have sold a thousand of thier cameras, and the same is likely true for every other pro. We are more than the icing on the cake, we are Canons proof of excellence.
If Nikon bring out the D4 and it betters what Canon have on the market I'll switch in a heartbeat because I'll have to. I can't make excuses for my gear, I have to have the best equipment, and if I don't my clients will not remain clients for long. The onus is on Canon to stay ahead, and by leaving us out in the cold for much longer they risk loosing their pinnacle spot in the very important Pro FF SLR market.
How would you feel when you go to a game, an event or whatever, and all the pros are shooting Nikon because it is better? You'll start feeling your on the loosing team. Trust me. I know, that is what happened to me when the EOS came out back in 1991. I was all Nikon until the F4 dropped the ball, and Canon grabbed it and made a home run. It took about one year for every camera at the sports events, concerts, fashion shows, you name it, to go from Nikon to Canon.
We have to have to best, because we can't let our competition have anything better, and trust me, you'll want what we're using, even if you think we don't matter.