Deryck Chan, 14/07/2012 00:51:
If I remember correctly they started uploading videos to Commons and YouTube almost immediately after the conference, though it is only 2-3 months later that all the individual lecture and panel videos were up.
Videos on YouTube have been uploaded soon, but the full coverage only two months ago, not before making a WMF server crash to convert them. In the meanwhile, of course interest dropped so that nobody split the videos in usable format (per talk) and they're not even included in the wiki. Example: https://commons.wikimedia.org/wiki/File:Wikimania_2011_-_Day_1_summary_video.ogv
Nemo