Mango not only promises to bring 500 new features for regular users but also numerous other languages for the rest of the planet. For those who want some Japanese on their Windows Phone now, or perhaps those looking to explore how to add other language, a neat little hack has appeared over at NanaPho.
The trick requires a registry edit before you upgrade to Mango (you can't yet edit the registry on Mango devices, as far as we know) and may be good for those playing with DFT's custom ROMs. While in NoDo or earlier, simply launch the registry editor and make these changes:
1. add this entry on your NoDo (7390 or 7392) phone.
2. update to Mango Beta 2 Refresh
3. you will get Japanese language
Of course the potential is there to add other languages, though it has to be verified. Other language packs which are made available with the Mango release include 0413 (Netherlands), 0419 (Russian), 0804 (Simplified Chinese), 0404 (Traditional Chinese) and in theory, those should work too. Looks to be a cool trick for those not wanting to wait the extra month or two for the RTM Mango to hit.