Microsoft's Windows Phone Mango press release hit the wires a little early, courtesy of Microsoft Romania , and now we have all the details from the event. The update (which Microsoft is just calling "Windows Phone Mango, with no "7" just yet) will be available to all Windows Phone 7 handsets in early fall, and a beta SDK should be out in the next 24 hours. Here are some of those "500 new features" we can expect:

Messaging

• Synergy-style integration of messaging apps (one conversation thread for multiple messaging mediums), and contact integration with Twitter and LinkedIn.
• Group messaging Live Tiles (like "Family" or "Friends") with group chat over Windows Live Messenger and Facebook chat.
• Combined inbox.
• Speech-to-text and text-to-speech for messaging.

Apps

• Apps show up in hub search results.
• Live tile improvements allow for more information and more live updates without having to open the app.
• Multitasking.

Browsing

• Internet Explorer 9, with HTML5 and hardware acceleration features.
• Local search.
• Bing Vision, Voice, and Music search. You can take a picture of a book, for instance, and go straight to buying that book for Kindle.
• Something called "Quick Cards" that sounds kind of lame.

Hardware

• We aren't supposed to see any hardware at the event, but the press release promises partnerships with Acer, Fujitsu and ZTE in the future.

Check out our Windows Phone Mango hands-on!