Thanks to Jim for pointing this one out to me. It looks like Portable Firefox has a new edition out with some awesome features not seen before.
Portable Firefox is now Mozilla Firefox – Portable Edition (Firefox Portable among friends), and version 188.8.131.52 has been released. It’s the popular Mozilla Firefox web browser packaged with a PortableApps.com Launcher as a portable app, so you can take your bookmarks, extensions and saved passwords with you. This new release adds in a ton of new features, including: the ability to run from a CD, complete Firefox partial update support, in-place upgrades, lots of handy bug fixes, support for running within Wine on *nix and more.