Even if they did make the 1D/1Ds the flagship video camera, people would just go and buy a video camera at $7000-$10,000. The draw to the 5D Mark II for video is the $2500 price tag.
well, not quite...
it seems that the sensor on the 5D2 is much better than anything panasonic or sony could make at the moment; for example, Shane Hurlbut (ASC, big canon DSLR kool-aid maker, take with a grain of salt) said something to the tune of "canon has been making sensors for 20 years, the others are new to the game, the images just don't look the same, they can't compete quite yet"
and mind you: these are not people obsessed by resolution, but by dynamic range and things like "organic look", "color" and "falloff"
they do want the videocamera ergonomica (XLR inputs, SDI outputs, histogram, waveform, zebras, peaking, etc), but so far they've been happy exchanging all that for a better image
still: for me, yes, a sony F3 is out of my price range, and a 1Ds would be too; a 5D3 withoug aliasing/moire would be more than welcome