The site  mimovilwindows said to have received some news on the release of a Windows Phone Tango for existing smartphones from a reliable source. According to reports, upgrade to Tango is ready and pending approval from the manufacturers and mobile operators. The build of this new version should be the Zune through 8773 and the release should arrive at the beginning of the month of June 2012.

Another info that we can read on the site is that Microsoft probably decided to move the release of Windows Phone Tango expected this month in the month of June, to allow more time for all operators to approve the update and release it all in a very limited time.