Microsoft is set to unveil Toshiba-Fujitsu IS12T Windows Phone , the first WP7 handset officially running Mango at 10 AM Tokyo time on Wednesday, or 8 PM CST Tuesday.Toshiba Fujitsu IS12T will pack a 3.7-inch LCD display.This is an important occasion as the IS12T marks the start of the second generation of Windows Phone hardware, and signifies that the first chapter of WP7 is over.

The following image is of the announcement:

The Mango update for Windows Phone devices is said to deliver over 500 new features including such things as Twitter integration, turn-by-turn navigation, fast app switching, Windows Live Messenger, and of course if it is destined to play on Japanese Windows Phone devices, language support.

The event will be livestreamed, with Ustream powering the feed.

Source: thenextweb