As another suggestion similar to the one I made previously, it'd be nice to see perhaps who's idling on the forum at any given time. That would be helpful once direct messages are implemented, or perhaps just the ability to post back and forth with people in a more fast-paced manner because you know they're there, too.
Viewing post in Forum Suggestions
Well, I guess two things.
1) An icon by their name indicating if they're online (viewing the forum) or not.
2) A list or count of users currently online. I like the simple look and feel of the forums so far, so I wouldn't really sacrifice that for a long list of names, but knowing how active the forums are would be nice for maximizing views and activity.