Unfortunately I have to be the bearer of bad news and tell you that Firefox 2 Beta 1 will not be released today. Linux News reported this last night and said Mozilla will release Beta 1 later this week.
If you don’t want to wait any longer then you can download Firefox 2 Beta 1 Release Candidate 2 that Mozilla made available yesterday. I have also made a portable version of this build for those people looking to take a slightly safer route to testing. After you have it up and running you can start to tweak it with a guide that I put together. In the guide I cover some features like removing the close button from every tab or forcing Firefox to restore your session each time you restart the browser. At least Mozilla has made some things available to us that will tide us over until the official release!