I'm doing this currently in a # of ways, e.g. the related topics on the top right and messing with the Yahoo BOSS results (under the human powered results) using information from the Wikipedia topic. I'm of course very interested in ideas for how to do more.

have you looked at getting data from freebase instead of wikipedia?

Indeed. Nothing to show for it yet, but I'm looking at freebase to help power some of the technology in our next major version.

nice. can't wait to the see the next version.