Once we've managed to upgrade openacs.org to 5.0, we could learn from Drupal to make a few changes to our site design:
http://drupal.org/
Starting from the top:
1. Clean CSS-driven design. I like that the header uses a small font. Search widget (we have that, too).
2. A full paragraph explaning what Drupal is, with links to additional information: About, Features, Sites, Screenshots. I think we should have all four of those links as well.
3. Most of the rest of the page is dedicated to a weblog, which (obviously) has an RSS feed (btw, we should make RSS feeds of OpenACS forums)
4. "Development" box in right-hand side with links relevant for developers.
5. "Who's online", also int he right-hand side, which says "There are currently x users and y guests online".
Just some inspiration.
/Lars