Hey all, Firefox 4 got officially released yesterday and I upgraded a few hours ago. I figured out a method to get it to run and built a package using the same trick. You can grab it here: http://www.box.net/shared/j9kcfueb9a - you can install it the normal way by using tazpkg install firefox-4.0.tazpkg
Now a few things. I haven't tested this on a clean system and it may be missing one or two dependencies. I also intially used it to upgrade my system to the new firefox, which might mean you need to have a working copy of Firefox before installing this package. Also I will not fix it if it's broken. I'm sorry, but it's an 11.2MB upload every time and it takes a while on my connection.
Anyway, now you all can finally be smug towards other distros for a while...
That's exactly what the above does. It just places Firefox so it can be used system wide and creates the icon for it. It's better than having Firefox just running from somewhere in your home folder :|