just bought a Canon 5D. shot this video of my friend playing acoustic guitar in a stairwell.
I edited in Premiere with some minor color correction using Magic Bullet. Colorista is indeed really handy but it doesn't always achieve what you're looking for. In this case it seemed to work okay. Also, as Pete mentioned above, the Canons always seem to fade to the red side (one of the major ways the LCD viewfinder lies to you, another one is ISO noise) so when you use Colorista to color correct you sometimes lose a little brightness and detail.
I used to be a FCP guy but CS5 works better with DSLR footage so I made the switch. the audio was recorded with two condenser mics, which I synced with an additional shotgun mic on the camera. the lens was 24-70, except for one outside shot with an 85.
the 5D is rad, can't recommend it enough.