We've talked about implementing HD quality videos for a long time and finally they have arrived. It will take a while for our system to render all 30,000 videos in HD, but you will notice more and more making the quality jump.
Another very cool change, is how we handle "related" content on game, development groups and engine profiles. At the moment news and downloads only show up in these profiles if the content is directly associated with it. From now on however, if you post news about your mod for Half-Life, that news will show up in the Half-Life profile as it is in-directly related. The same applies for your development group, news you post to your game profile will show up there. This change should help interlink content across the sites a lot better, and make game, engine and group profiles feel a lot less empty.