Microsoft has just dropped us a line to note that Fujitsu and KDDI au have released the IS12T in Japan, becoming the first Windows Phone 7.5 (codenamed "Mango") handset to hit retail anywhere in the world. It's a little surprising considering that the updated Marketplace for Mango was just opened to third-party developers yesterday -- buyers might have to wait a few days before 7.5-specific apps start becoming available -- and interestingly, Microsoft says "some of the experiences associated with Windows Phone 7.5 have yet to be fully enabled," though it doesn't lay out the full list of what's missing at this point. Hopefully, this means a final build suited for a more global launch is imminent, but the company isn't tipping its hand on that just yet.

Source: KDDI au, Fujitsu