As stated on the Mozilla.org Firefox projectpage:
Firefox 1.5 Beta 1 is now available for download. This is the first Beta release of our next generation Firefox browser, to be released later this year, and it is being made available to our developer and testing community for compatibility testing and to solicit feedback.
Note: This is not the final release of our Web browser, it has been made available for testing purposes only, with no end-user support. If that sounds scary, you’d probably be better off with the latest version of Firefox 1.0.
Installing it on a production environment generally is a bad idea as it will break a lot of your extensions. But if you’re dying to take a look, do so here.
The roadmap states there will be a Firefox 1.5 Beta 2 following in October. So it should be safe to say that the final 1.5 will be available before the holiday season? *knock on wood*
Surprisingly *the other browser* is due for release around ‘Mid-Late Q4‘. Are the fox and the e about to clash at the end of this year?