Deaf

That is a hard question to answer. Do you want to host the video yourself or send folks to a site like YouTube to upload video and just post it as a comment? Do you really mean comments in the sense that you want threaded responses to an individual post, many of those responses in the form of embedded videos? Or do you want to invite people to submit video commentary on specific topics?

You could make it work in Drupal, but that doesn't really answer your question about whether Drupal is best. I think that depends a lot on what else you need to be able to do with the site.

Once you get several hundred videos you can make use them to build a sign language tutorial. :)

There are modules that make embedding a video from any of the popular services or from a custom source as easy as cutting and pasting a url.

I set it up at my site. Required CCK and emfield modules.

I there is a module that uses flash to take a screen shot from web cam.

I don't know of any video capture add-ons for any CMS.