We need a dev tracker that has all the posts from the staff so we can get that information quickly. I want to add that we don’t want to take dev resources away from DnD Insider. I do not know if the forums share dev resources or not.
Up on the top menu, click on "My Account" and when the menu comes up select "View the Member List."
When that comes up, on the right hand side of the screen, just under where it tells you how many pages there are, is a "Search Members" link. Click on that, then type in the name of the person you're interested in. When the names come up, click on the user's name and it'll take you to their public profile. If you scroll down to the "forum information" section, there are links to find all posts by the user, or all threads started by the user.
Alternatively, if you can easily find a post by the user, you can simply click on their name in that post and then select "View Public Profile" and you'll get the same information.
Note that this works for any user, not just staff. If you wanted to know what your favorite poster on the forums has said recently, you can use this method to find all his/her posts as well.
I know it's not quite what you wanted, but that's about the best that exists right now.
Please, please give us a Dev Tracker.