OK, search will now default to the languages you selected in your profile, if you are signed in. If not signed in, we will try to pull languages out of the header accept-language field in the request, and give you the option to filter by those languages, but we do not default to them.
Sorry this took so long to release. It has been mostly finished for some time now, but I got caught up in TechEd.
Let us know if this is working the way you all would like it.