A Windows Update is available to users who are located in member countries of the European Union allowing for choosing a different standard browser for the system. The update is available for download through Windows Update. Read more here: http://techblog.avira.com/2010/03/08/the-browser-choice/en/
After writing this article ( http://techblog.avira.com/2010/01/04/firefox-extension-updates/en/ ) and after Dirk’s info , it finally happened to Firefox: They published malicious plugins It was just a matter of time 😉 Short link
Yes, I got it 😉 PRO: it is better in rendering, it is faster. Zooming a page works perfectly this time. CONS: I think it eats more RAM than its predecessors. One single TAB requires 100 MB RAM and 78 MB VM. Firefox 3.0.11 needed about 80MB RAM with the same plugins and theme.