Dave Winer and Robert Scoble would like more blog outputs as OPML. I just put together a Movable Type template to output all of my entries in OPML format complete with top-level categories. I output the resulting file as my index.opml.
Check out my OPML template if you would like to create a OPML output of your Movable Type install. I have not validated the OPML is perfect and valid (but I did e-mail Dave Winer), and I really should have full subcategory traversal. It’s a start.
Update: Dave Winer verified the output is correct and works with his browser.