As Firefox Portable isn't available in every language supported by Firefox, I'd strongly recommend/suggest that the Locale Switcher addon by Benjamin Smedberg - https://addons.mozilla.org/da/firefox/addon/356 - is included by default, to make installing and switching the language in Firefox way easier to the users.
The add-on is very small, just 3kb, but rather important; most FF-users know they can get their own language as an XPI addon, but we've had several questions on how to activate it after installation on the danish Moz support forum, and this tiny thing would solve that permanently.
Also, I'd love to see the danish Firefox on the list of versions, but generally I think above suggestion is more important.
Keep up the great work here on PortableApps!
not allowed by the agreement john has with mozilla. He can't modify what he puts up for download.
Too many lonely hearts in the real world
Too many bridges you can burn
Too many tables you can't turn
Don't wanna live my life in the real world