If you need to run Firefox before March on your OSx86 machine, there are a few possible choices:
1. Use Apple's Rosetta to run a PowerPC version of Firefox.
2. Run the preproduction OSx86 version of Firefox Josh Aas and other Mozilla developers have been working on since last year. Note that you will be required to disable the use of Flash and will be without the use of some Java Applets with this version.
Also available in a preproduction Intel Mac OS X version on the same Mozilla wiki is their mail client, Thunderbird for OSx86.
The ZDNet article also mentions that Apple has been very helpful to Mozilla developer Josh Aas with the process of creating native builds of Mozilla software for OSx86. Props to Apple and Macromedia for cooperating with open source development!
[via ZDNet Australia]