Let's pretend we know the following:
Nikon's next gen D90 will be called the D7000.
It will be an upgraded version of D90.
1080 HD video w/AF
Somewhere between 6-8 fps
Improved ISO range: 100-25600
39 AF points
Price: $1199 for body only
If you are currently in Rebel or xxD body how closely will you look at the D7000 as described above when it is time to upgrade? Your Canon mount lens investment will certainly play in to this, but I can't see how it wouldn't be tempting if you care about video. For me it will all be about video. I want it, but it has to be done well. I am not going to pay Canon, Nikon or anyone to "upgrade" from my 50D for video and end up with something that will still have me reaching for my old HF10 camcorder. I've always thought Nikon would be the company to offer optimized video in a DSLR, as they don't have any camcorder sales to cannibalize. We'll see if the D7000 does the trick.