It probably isn't a huge loss in the grand scheme of things, well minus the people who handled that end of their (Google's) business exclusively who might be out of a job, but I do recall a handful of videos that were exclusive to Google video that had never made it onto YouTube.
Mostly tv and movie clips, but still it served as evidence that YouTube doesn't contain every video a user could ever want (there is a lot of stuff I've tried to find on YouTube that I've had no success locating either because it has never been uploaded or if it has the Title and/or Description are so poorly composed that it is impossible to locate via a traditional search and you can only locate it on accident).
Now if Google defies all odds and somehow finds a way to forever "shut down" the rambling, unfocused, directionless "run on sentence" (as seen ^^^^^^^), I'm gonna be pissed.