Microsoft’s highly anticipated Windows Phone 7.5 “Mango” update is now available to download.

The software giant started pushing out device updates to a range of carriers worldwide on Tuesday as part of a global push for existing Windows Phone 7 users. Windows phone 7.5 “Mango” brings over 500 new features to the Windows Phone platform and improves hardware support for new devices. The majority of U.S. and worldwide carriers have completed their testing with Microsoft and the software maker started pushing updates out on Tuesday. Existing Windows Phone 7 users will be notified by an on-screen prompt that an update is available for their device.

Microsoft says the update process for Windows Phone 7.5 will take a few weeks and that the company expects all Windows Phone 7 users to receive the update by the end of October. Microsoft’s hardware partners are planning to launch a number of new Windows Phone 7.5 powered devices in the coming weeks. Nokia, Microsoft’s strategic Windows Phone partner, is also set to unveil its first Windows Phone device at Nokia World 2011 in mid-October. Confirmed Windows Phone 7.5 devices are:

• HTC Radar
• HTC Titan
• Samsung Focus S
• Samsung Focus Flash
• Samsung Omnia W
• Nokia “Sea Ray”
• Acer W4
• ZTE Tania

Microsoft’s Windows Phone 7.5 update will bring a number of features to existing Windows Phone devices. Microsoft has improved its mobile browser by porting over Internet Explorer 9 from the desktop. Windows Phone 7.5 now supports HTML5 and hardware accelerated browsing to bring an improved surfing experience to mobile. Microsoft has tweaked every part of Windows Phone 7 and has added some impressive improvements along the way. Bing Scout, Bing Vision and Bing Audio are now all available in the Bing section of Windows Phone. Bing Scout will provide easy and quick access to restaurants and places of interest near a users location. Bing Vision will allow users to scan in barcodes, QR codes, books, CDs and DVDs to quickly find the product at online retailers. Bing Audio, similar to Shazam, will allow Windows Phone 7.5 users to quickly identify an audio track and instantly stream it using Microsoft’s Zune music service.

One of the noticeable features of Windows Phone 7.5 is the ability to multitask across the operating system. Developers can now take advantage of this in their Windows Phone applications. The convenience and fast switching will likely be a catalyst for a number of new Windows Phone 7.5 applications that take advantage of the new support and many other APIs that Microsoft has enabled with its update. Developers will also be able to target new forward facing camera hardware to create video calling applications. Microsoft revealed earlier this year that Skype is planning to launch its own Windows Phone application with Mango so expect to see that shortly.

Microsoft’s tweaks also extend to the various hubs in the operating system. The messaging hub now includes threaded messaging and Windows Live Messenger and Facebook chat integration. Microsoft has made it easy for users to switch between their instant messaging services and traditional SMS. The thread feature of Windows Phone 7.5 will also intelligently switch services when a user is available on Windows Live Messenger or Facebook chat. Microsoft has continued its improvements in the People Hub by adding Twitter and LinkedIn integration. Windows Phone 7.5 users can choose to filter out the what’s new page in the People Hub down to specific social networks and can enable and disable Twitter and LinkedIn contact linking in a similar way to the existing Facebook support.

Windows Phone 7.5 Office hub and Xbox hub improvements see the company add exciting features for both business and consumers. The Office Hub now includes support for Windows Live SkyDrive support and Office 365. Business Windows Phone users will be able to sync their documents and edit files on the go. Consumers will be able to quickly and easily sync their SkyDrive documents onto their Windows Phone. Microsoft’s mail support is also greatly improved with conversation view and the ability to group various separate mailboxes. The Xbox gaming hub is improved in a number of ways. Microsoft now supports game addons and avatar awardables. Xbox LIVE users can purchase additional items for their avatars and Microsoft has introduced full avatar support in the Windows Phone 7.5 update. The Xbox LIVE gaming hub also includes the new async Xbox LIVE service that improves gameplay for multiplayer, turn-by-turn (or asynchronous) Windows Phone games.

We’ve only touched on the basics of Windows Phone 7.5 here, fire up your Zune client and grab the update for yourself to truly explore all the improvements that Mango brings.