Mi Móvil Windows claims from their “fountain of reliable information” that Windows Phone 7.5 Tango/Refresh will release in the first days of June 2012. The website even goes so far to say that this release date window is definite, but we will take it as a rumor until anything official releases.
The folks at Mi Móvil Windows go on to mention that Microsoft has moved the initial April release back to June for the purpose of all carriers to prepare the OS update for a synchronized release. The synchronized release will still require Zune to update, but will be available synchronously for world, unlocked, and contract phones.
We shall soon find out if this is a rumor or not, hang in there!