this is an excellent idea, i think! something like "in other news..." and then show a little sample of recent posts from other topics. granted the "news" features of sito are meant to be THE place for seeing, well, whats new; however, a little encouragement to explore sideways on sito is always good.
in fact, such a feature might be great in the artchives as well. however, ed and i have TOO many ideas of artchive-browsing methods we want to explore. i will add this to the list. gosh, we really need to make the artchives browseable in about 1000 ways... ugh.