As of this writing the Firefox 2 Beta 2 download page doesn't link to it but with this URL you can download Beta 2. I have been using Beta 1 ever since it was released and really came to like it (especially live, inline spell checking). So what does Beta 2 bring to the table you ask? A nicely refreshed look - new icons and tab styling. However, I do think that the updated look lacks contrast in the navigation toolbar.

As for other features new in Beta 2, there is support for Live Titles on sites with microsummaries in addition to support for JavaScript 1.7. Check out the release notes to learn more.

Update: I forgot about the Windows users... Firefox 2 Beta 2 download link.