Firefox 0.9 has been released today. Of course I immediately downloaded and installed it. As the version number shows, this is still a technology preview, so there still are some things not working quite as they should.
The most important missing feature is a good installation procedure. To upgrade from version 0.8 to 0.9, I had to remove the old version, install the new one and after that I had to reinstall all my extensions — Bookmarks synchronizer, Bloglines notifier, Links toolbar. All together 10 minutes work to upgrade a simple application.
But alas, this was the last time I had to go through this, since the next version will hopefully be 1.0 and will include the upgrade functionality.