English (US and UK), French, German, Italian, Spanish, Danish, Dutch, Malay, Russian, Slovenian,Portuguese (Brazil and Portugal), Romanian, Slovak, Swedish, Serbian (Latin Keyboard), Czech, Greek, Polish, Indonesian, Norwegian (Nynorsk and Bokmål), Turkish, Icelandic.
Early 2010 we'll be adding in the following:
Croatian, Finnish, Bulgarian, Hungarian, Ukranian, Arabic, Hindi, Vietnamese, Japanese, Chinese - Mandarin (simplified), Korean, Urdu, Farsi, Estonian, Catalan, Latvian, Filipino (Tagalog), Hebrew, Galician, Lithuanian, Thai and a few more.
If you don't see your language listed, keep in mind we're developing languages at the request of our partners and customers. Also we only install the languages that an OEM has requested on any given phone - so from phone to phone and country to country you will see a different combination of dictionaries.