Microsoft will begin rolling out its Windows Phone 7.5 Mango update starting within the next two weeks. The update will likely be rolled out in batches with select devices being supported first. When Mango is ready for your device, you should receive a message on your phone, but you can also check the "Where's my phone update?" page for the status.
Along with the Mango update, you will also be getting new firmware from your handset manufacturer. This new firmware has been fine tuned to ensure that your phone and apps are compatible with all the new features in Mango. Hence, Microsoft encourages users to avoid bootleg updates that may not allow your phone to function properly or optimally with Mango.
The update will not be over-the-air, which means you will need to download and install the update yourself. Microsoft is offering new version of the Windows Phone 7 Connector for Mac as well as for the Zune software for PCs, which have been improved to speed up the update process and to allow for more control over backups. Either one of the apps will be required to update your phone.
[via Windows Phone Blog]