There are now several sites and Google Groups related to the Khan Academy. Here's what they correspond to:
http://www.khanacademy.org - the Khan Academy!
http://sites.google.com/a/khanacademy.org/forge/ - information relevant to people who are building, maintaining, or contributing to the Khan Academy.
http://groups.google.com/a/khanacademy.org/group/translators-discuss - for discussion among people helping with the translation effort.
http://groups.google.com/a/khanacademy.org/group/outreach-discuss - for discussion among people helping with outreach/promotion.
http://groups.google.com/group/khanacademy-developers - for discussion among people developing the Khan Academy application.
http://groups.google.com/group/khan-academy-developer-notifications - read-only group for getting notifications about code changes and code reviews.
http://groups.google.com/group/khan-academy-support-offers - where emails offering support end up.
http://groups.google.com/group/khan-academy-feature-requests - where feature requests end up. Developers monitor this group and copy new feature ideas into the issue tracker.
http://groups.google.com/group/khan-academy-topic-ideas - where ideas for topics to be covered end up. We monitor this to gauge which topics are in high demand.
http://groups.google.com/group/khan-academy-comments - where other comments go. The comments are generally very positive, so this is a great place to go to for motivation.