On the forums, browse/site-map, about, and links pages, you'll notice a new right-hand navigation pane with a listing of all-time most popular content and, on the forums and browse pages, recent comments.
It's a little misleading, because the comments can be comments on any node--not just a forum topic. So, if someone publishes a lesson or CD review, recent comments might be on that lesson or review instead of in the forum per se, but the strategy here is to let people easily see what's new and what's popular.
I didn't want to crowd the layout, so I only added the right-hand nav to the top-level of the forum page and didn't include it on the front page or any of the lesson/interview/review pages.
Hope you like it,