In a blog post Microsoft has detailed some of the internationalization features of Windows Phone 7 Mango.
Microsoft announced the 22 display languages in total will be supported for the user interface, up from 5.
This includes: English (US and UK), French, German, Italian, Spanish, Brazilian Portuguese, Chinese (simplified and traditional), Czech, Danish, Dutch, Finnish, Greek, Hungarian, Japanese, Korean, Norwegian (BokmÃ¥l), Polish, Portuguese, Russian, and Swedish. The exact languages available to select in your phone will depend on your operator.
The Zune desktop software will also be available in the same languages.
In terms of input languages 25 will now be supported, adding Brazilian Portuguese, Czech, Danish, Dutch, Finnish, Greek, Hungarian, Indonesian, Japanese, Korean, Malaysian, Norwegian, Polish, Portuguese, Russian, Simplified Chinese, Swedish, Traditional Chinese, Turkish, and Ukrainian.
Text prediction will be available in Brazilian Portuguese, Danish, Dutch, Finnish, Greek, Japanese, Korean, Norwegian, Polish, Portuguese, Russian, Simplified Chinese, Swedish and Traditional Chinese.
RTL languages are still not supported, but Microsoft has promised to continue working on it, noting several controls will have to be re-worked to make this possible.
Marketplace itself will be expanding to include 35 countries: Australia, Austria, Belgium, Brazil, Canada, Chile, Colombia, Czech Republic, Denmark, Finland, France, Germany, Greece, Hong Kong, Hungary, India, Ireland, Italy, Japan, Korea, Mexico, Netherlands, New Zealand, Norway, Poland, Portugal, Russia, Singapore, South Africa, Spain, Sweden, Switzerland, Taiwan, United Kingdom, and the United States.
Other Xbox Live services will also see expansion, with the Zune Marketplace for music, video, and podcasts is expanding to more markets. Microsoft was not ready to share details yet.
Lastly, Microsoft also detailed where specific Windows Phone 7 features will be available:
He notes that Microsoft will continue the challenge to expand their services, and ultimately aim to make the services available worldwide.
Read a lot more detail at Microsoft here.