Things can change quick in digital. Nikon was behind in many aspects, came back and I think is doing with the 3D in many regards better than Canon. Competition is good for us costumers as prices might go down, or features improve.
What is worrying me as a Canon shooter are the in my opinion bad wide angle lenses of canon (like 17-40 or the 24 TSE which I and other photographers I know think is useless on a high resolution digital body) So while Canon has a lot of lenses a lot of these do not make much sense to use beyond or even with 12 MP. The same is with other companies, the cheap lenses are often not build to the task to support high resolution sensors, nothing to complain about this, but they do not have pro lenses in a useful range or do not have them at all. Sony with corporation to Zeiss might be capable to build up a strong professional lens line up which matches the needs of an 24 MP sensor, but this is at this point pure speculation. The sucess of the Nikon D3 in my opinion is not about the high iso hype for me (as this camera might be a sensation to nikon shooters, but for a Canon shooter good high iso performance is nothing new). The interesting thing is, that Nikon in a way is introducing a totally new digital system. Yes you can use your old lenses, but the new lenses like 14-24, 24-70, and especially the new announced Tilt/Shift lenses with the magnetic aperture control (only working with D3 and D300!) show that Nikon has clearly seen the necessity of a new lens line up if you want to get the best out of high performance sensors at 12 MP and beyond. Canon is thinking they can sell us the old stuff on and on with with a very sloppy quality control (so you have to go to a shop, test three lenses of the same kind and hopefully one is good - like buying three cars and hopefully one is actually driving ?) I have tested the new 1DsMarkIII for a week and I could afford to buy it. But I wont do it, for now I will stick with my good Canon kit (5D and 40 D and some lenses which do the job, because I use a tripod and use the lenses at aperture 11 or even 13 and 16 like the 17-40 L at 17 mmm). If I decide to go into higher pixel counts I do not see for my kind of shooting a future with the Canon system, the cameras are great, but too many of the optics suck. I do not adapt nikon optics to Canon, if I think the nikon optics are better, I buy the Nikon camera too. Sadly from some talk to Canon reps I think they simply deny that some of their optics are not up to the task, and updated optics like the 16-35 are not that much better, it seems like they have their weak point here. Hopefully I will get the Nikon D3 and the 14-24 and 24-70 for testing to see for myself, if Nikon is doing better with their optics (and hopefully with their quality control) as some pro photographers are claiming. And as stated above, if Sony is building up a professional lens line up together with an 24 MP body which is not as heavy as the 1d series, many landscape shooters will be very interested in this system. As seen with the new announced 24-70 2,8 Zeiss-Sony lens it will be as expensive and as heavy as similar lenses from other companies.
The hype about image stabilization I do not understand. My tests showed that while it makes sharper pictures for times like 1/8 to 1/60 the point is they are sharper but still unsharp - no compare to a well done picture from a tripod (exception are tele lenses like 600 mm, there is works also with shorter times). So for me built in IS is an amateur feature I do not need (aerial pictures for example do not benefit from IS, a fast shutter speed is much more important - so lenses which are tack sharp wide open and good high iso perfomance do help more).