I'd love it if someone on the team who supports the wordpress.org forums could add the ability to receive email notifications when someone answers a topic you've created.
Also, and tongue slightly in cheek, it would be great to see a slightly less "mood deadening" theme used for wordpress.org. I don't know why, but every time I come here I think, "grandma's wallpaper". The site has had the same theme for the couple of years that I've been interested in WP. Maybe it could be the subject of a competition? This is assuming that it's somewhat based on WP itself.