Following Office 2010 launch, Microsoft announced that "Terminology and UI strings are now available for the first 18 localized languages on the Microsoft Language Portal." Languages included are: Arabic, Brazilian, Chinese Simplified, Chinese Traditional, Danish, Dutch, French, German, Hebrew, Hindi, Italian, Japanese, Korean, Polish, Russian, Spanish, Swedish, Thai.
Additional languages will follow later as the Office 2010 localization team wraps up more languages. By default, a search on the Language Portal display results from all products, including Office 2010. To narrow your search to Office 2010 terms and strings only, select "Office system" in the Product drop-down: