Windows Phone 7.5 Mango is now apparently officially out in Taiwan. The update process is somewhat non-conventional though: HTC users who wish to update their HTC Mozart or HTC HD7 will have to go to their HTC store to get their device updated or grab the RUU firmware file from there. There’s no update through Zune yet because it apparently won’t include the Asian language support. the two firmware files are the following:
Big thanks to Jas for the info
EDIT: To be perfectly clear; The Mango update roll out will start this fall.