Excellent.

How about something to get favicons next to bookmarks? I find it an odd design choice that they appear for History but not the bookmarks menu.

Does anyone know how to create Smart Folders in the Bookmarks menu? FF3 starts with a few already (such as "Recent") but if I delete them, I can't see a way to put them back nor make new ones.

In general I don't really like the Bookmarks editing window and find it somewhat unresponsive compared to native windows. Safari has done this better in my opinion, but then again, FF bookmarks can have more metadata associated with them (like descriptions and tags).

I notice that FF lacks polish in a number of areas and that's where many add-ons really shine. One thing I noticed after a few minutes yesterday was that there still exists problems bringing the Firefox window into focus. It might launch behind other applications, won't come to the foreground when certain parts of the UI are clicked, window can only be dragged by clicking at the very top of the title bar (Other Mac apps can be dragged by any part of the unified title/tool bar).