When I view the 1080p MVIs from my dslr with quicktime player (under windows 7) I am seeing the images I desire from the camera. However, when I import those very same files into cs5 Premiere, the images appear horribly crushed---very dark and full of contrast. Can anyone explain why this is happening?

Simple: Quicktime screws up the Gamma which lifts the blacks and reduces contrast. What you see in Premiere is your actual video and if you want it to look more like Quicktime, then a simple Gamma correction effect or adjust Gamma within the Levels effect.

This Quicktime 'issue' is something FCP users have had to learn to deal with for sometime now.

It seems that cs5 premiere is clipping the shadows and highlights on import. Apparently the only way around this is to employ cineform? I don't mind purchasing Neoscene since I'll be getting a first class editing codec and avoid the clipping issues.

Simple: Quicktime screws up the Gamma which lifts the blacks and reduces contrast. What you see in Premiere is your actual video and if you want it to look more like Quicktime, then a simple Gamma correction effect or adjust Gamma within the Levels effect.

This Quicktime 'issue' is something FCP users have had to learn to deal with for sometime now.

Hmm. Are you saying there is no clipping, and that it is just a gamma shift alone?

it is very bad 0-255 rgb to 16-235 YUV conversion. Cineform does it great and in high quality. You also better lower your contrast to minimum in your DSLR when you shoot video. Default setting is made for photos and their normal 0-255 rgb range. So, crush contrast and colours for better results ( for canon use neutral picture profile)
bye