Unfortunately there is no Svenska. Language inclusion for Mozilla products is entirely community driven. Are you interested in starting some string translations for Swedish speakers?

https://developer.mozilla.org/en/Create_a_new_localization https://wiki.mozilla.org/L10n:Home_Page

After contacting a member of the Swedish localization team, I got to know that there IS a Swedish translation, but that it cannot be included until Firefox is shipped with only en-US, and the option of choosing one other language (see e.g. this bug: https://bugzilla.mozilla.org/show_bug.cgi?id=626023 ), since they want to reduce the size of the app.

However, I got the tip that the language settings in Firefox (defining what language web pages are shown in) can be changed through about:config, changing the entry "intl.accept_languages" to e.g. sv-se,sv,en-us

That solved most parts of my problem - using the search window now renders a search on google.se.

Firefox 10 should have our language switching feature implemented. This will allow us to reduce the package size while still giving access to Firefox in your native language. If everything goes to plan it will be in the market as Firefox mobile Beta mid-December and Firefox mobile late-January early-February.

comments deleted by a moderator - If you don't have anything positive to contribute which helps the "owner" of a question thread, please refrain from posting anything at all. If you need help with a problem of your own, please start your own question thread and ask for help. Otherwise you are interfering with the support process for the "owner" of this thread and that won't be tolerated here.