This is a real pain. If you want to quickly scan a bunch of clips in column mode (A real handy feature in all other versions of OSX), with "Quicklook" you can only view the clip from the beginning. Gone is the timeline/scrubbing function in which you can jump to any part of a clip (For Final Cut Pro users, this is a crucial function).

You can't adjust the volume, you can't do anything except watch the clips from the beginning. Again, video editors will suffer from this *deleted* function.

It's yet another 'helpful feature' Apple introduced with 10.5 in which you are now stuck with having to do more clicking (Which goes against user interface 101)

The finder in 10.5 has taken a real step backwards. It's designed to basically 'force' you to adopt their newer technologies: whether you like it or not.