Just FYI: I would also like to see FireFox ported to Amiga and actually researched undertaking the process of doing it myself (as Firefox is open source) so I downloaded the code and began looking into it. While I don't think it would be impossible, It is more effort than I myself want to put into because IIRC you would have to rewrite the graphics routines for the OS because Amiga does not use X-Windows. I hate the idea of having to find a way to run X ontop of the AmigaOS (like openoffice for Mac has to do).
It is a monster undertaking. Then of course, once someone decides to do this, they will have to support the offshoot - again I am not prepared for that kind of undertaking.
But It could be done if someone has their heart in it.