If the posts contain text from the presentation and/or are formatted for PerlMonks (vs. simply a title, link and summary) then I think it would be a good, no fuss, edition. I don't think there needs to be a new section for videos. You're simply posting a Meditation or Tutorial proposal that has a visual aid.

There are a few Perl themed channels on Vimeo including one for YAPC. It might be worth approaching the moderators for those channels in addition to (my preference would be instead of) the YouTube upload. Looking at the channels, most of them haven't been updated in a few years so new content might be appreciated :-)

In the case of Vimeo, and if the posts were made here like what I described, I don't think turning comments off there would be necessary. While it may seem like that would fragment the discussion, people going to Vimeo will more likely comment on specifics in the video I would think. Even if there were fragmentation, it's not likely to get out of control it possibly could if you did enabled comments on YouTube and have a thread here.