Just announced via Microsoft's PR channels, the Mango update is official now and has brought a host of new amazing features with it. Here's a quick look :
Fully integrated messaging alternating seamlessly between Windows Live messenger , SMS and Facebook Chat in the same conversation thread.
Local Scout gives you recommendations about nearby restaurants, places to shop and activities to do. Integrated into your search results.
Internet Explorer gets support for HTML5 and complete hardware acceleration, the ability to share web pages with your friends directly from the browser on social networks.
Windows Phone has also got the ability to make groups out of your contacts with the option for personalized tiles for the contacts. . See their latest status updates, conversations and you can also text, IM or Email the entire group in one go.
Finally a much-awaited feature by executives : a unified inbox. Combine all your mail accounts into one nifty inbox and access it through its tile.
Personal Contact card is like your personal one-stop on the phone to update your Facebook staus, check-in and update your IM status. And of course share it with others.
Bing Vision, Audio and Voice, which we reported earlier, offer new ways to search the net, integrated into the OS itself.
[Source]