On July 26, Microsoft made it official: The "Mango" operating system update for Windows Phones has RTM'd (released to manufacturing).
From a note on the Windows Phone blog:
"This marks the point in the development process where we hand code to our handset and mobile operator partners to optimize Mango for their specific phone and network configurations. Here on the Windows Phone team, we now turn to preparing for the update process."
I'm prepared to give Microsoft the benefit of the doubt and am counting on Windows Phone team members to have put the squeeze on their mobile operator partners. Hopefully, Microsoft has "convinced" them to sign off on the testing process quicker than they did with "NoDo," the first Windows Phone operating system update that took months to get into users' hands.
Mango, aka Windows Phone OS 7.5 7.1, includes a number of new features, including an HTML5 version of Internet Explorer 9 for mobiles; deep Twitter integration; support for private and beta apps; new Bing features; and more. MobileTechWorld has a nice list of the promised Mango features.
Microsoft's official announcement of the RTM of Mango happened just a couple of days after the Win Phone Dev podcasters heard (and broadcast) the news that the OS had gone final.
Update: A Microsoft WP evangelist tweeted that the RTM build of Mango was build 7720. His tweet later disappeared.
Update 2: While the Mango OS will be version 7.1 when it ships, the Mango handsets are going to be known as Windows Phone 7.5 phones. That's Microsoft's official (and final, I believe) word on the matter.