MozillaZine has announced that Firefox 2.0.0.5 has been released (though, as of this writing, I still don't see it via auto-update). I enjoy looking through change logs (weird as that may seem), so for every new Firefox release, I take a look at Bugzilla to figure out what has been fixed and what is new. Here's how I do it:

1. Browse to the BugZilla keywords description page (the link to this page is also available on the advanced search form).
2. Look for the "fixed[versionNumberHere]" and "verified[versionNumberHere]" keywords. Note that the [versionNumberHere] bit refers to the Gecko version number, not the Firefox version number. For example, Firefox 2.0.0.5 uses Gecko version 1.8.1.5 (as you might guess, the 2.0 release used 1.8.1). Firefox 3 will use Gecko 1.9.
3. Out to the right of each keyword, you should see a count of the total bugs that particular keyword corresponds to. Click that number, and you will see all of the bugs that use the specified keyword.

Here are the fixed bugs and verified bugs for 2.0.0.5. If you really want to get clever, you can combine these keywords together (separated by a comma) on the advanced BugZilla search page. You'll need to tweak some of the default settings on that form to get it to work, but it can be done (as this query for Firefox 1.5.0.5 indicates).

There are two special notes about doing things this way:

1. These queries are looking at fixes in the Gecko engine. As such, bug fixes for Thunderbird and Seamonkey will also show up.
2. You may not see everything, particularly high-risk security fixes. For all security changes, see the known vulnerabilities page.