Talk about major OS upgrade and we have Microsoft right up there. WMPU reports that Microsoft’s CEO while giving a keynote speech at the Microsoft’s Developer Forum 2011 in Japan revealed that the Mango update for Windows Phone will bring over 500 new features for the Windows Phone devices.

Bing Windows Phone 7

Ballmer also revealed that the Windows Phone 7.5 / Mango preview event scheduled for tomorrow will disclose the details of the OEMs and carriers that will be supporting Microsoft’s glance and go experience offering eco system. The Redmondians are expected to unveil a handful of new Windows Phone units tomorrow which makes Tuesday a very interesting day for smartphone enthusiasts across the globe.

More on this as it comes. Stay tuned and follow us on Twitter and Facebook to make sure you get the technology updates from Microsoft, Android and Apple world as and when they arrive.