Dave gave me some feedback on the new blogroll macro. A couple of corresponding changes were just made:
1) The default value for flProcessMacros was changed to false. If you were already using macros in your blogroll, add flProcessMacros:true to the parameters for radio.macros.blogroll.
2) A new optional parameter was added: flXmlButton. If true, then a little orange XML button linking to the OPML source for the blogroll will appear below the links. You can see an example below the links on the left edge of this page.
To get the changes, update Radio.root.
In case you missed it, here are the docs for radio.macros.blogroll.