Two quick suggestions for how you too can make this git annex repository better:
Both of these will increase the quality of the repo for everyone. cd into your local copy of the repository and run:
git-annex fsck --fast --from web >> ~/repo_fsck.txt
this will search through the repository and will check each and every file and video checked into git-annex to make sure that every file with a url exists where it should and can assumably be downloaded.
git-annex find --not --in web
this will search through all the files checked into git-annex and make sure that they have a url that they point to and will only print out the files that don't have any url target.
A short list of sites that host videos from conferences from past years that can also be added to the repository: Debian Australian Linux Conference FOSDEM LibrePlanet