One of the features I'd love Channel 9 to implement is a What's New page. I've found forum threads I've participated in get pushed down due to the volume of users on the site. This makes maintaining debates and expressing opinion difficult.
Each thread on the forums has its own RSS feed, which is a great feature. So how about, for each user, we have an OPML file. In this OPML are listed all the RSS files for the forum threads the user has participated within, or has marked to "watch".