Microsoft is planning to release an updated Windows Phone Mango build to developers.

The company is currently working on releasing a new build according to Cliff Simpkins, a Windows Phone 7 Product Manager at Microsoft. ”We’re working to get devs an updated build soon. Stay tuned to the dev blog,” said Simpkins in a comment on Microsoft’s Windows team blog. Simpkins also appeared to hint at an announcement within 24 hours in a twitter message on Tuesday. “Give me a day to get an official answer for folks,” said Simpkins in reply to questions on Windows Phone Mango RTM bits for developers.

Microsoft announced on Tuesday that it has officially finalized Windows Phone Mango. The update has now been released to manufacturing, the final phase in development. OEMs and carriers now have access to the final build (7720) which will be released to consumers this fall. Microsoft is planning a launch event for a Japanese Windows Phone Mango device in just a few hours. A Fujitsu branded Windows Phone will be made available in Japan by the end of August according to recent reports. The device will launch with carrier KDDI. The press event will be streamed online with partners KDDI and Toshiba-Fujitsu. Microsoft is expected to reveal the Toshiba-Fujitsu IS12T Windows Phone device to the Japanese market. Microsoft previously revealed the new phone during its Worldwide Partner Conference earlier this month. The device is water-resistant and is expected to feature a 3.7″ LCD screen and Qualcomm MSM8655 chipset. The phone will support GSM900/1800/1900 and CDMA2000 networks.