With a final for Firefox 0.9 around the corner (should be Monday), you can download there first RC from this FTP site.
The 0.9 release also includes the new theme by Kevin Gerich and Stephen Horlander called Winstripe which personally even though looks crisper than Qute, i don't think looks as good.
Also the Mozilla suit have released RC 3. The 1.7 branch now being the stable branch replacing 1.4, and also the basis for Firefox 1.0.