Android 2.2 also brings faster app-switching and support for Adobe Flash 10.1, allowing you phone's web browser to fully run websites that use Flash for navigation, games and video. In order to access the update, you will receive a message on your phone's notification bar. Just download the update, wait for it to install, and you should be all set. According to Google, the update will be rolling out gradually to all Nexus Ones during the week.
No specific date has been set for when other devices will get the final version of Android 2.2. The HTC Evo 4G, HTC Droid Incredible, and HTC Desire (non-US) should all be getting the update in the coming months, as well as the Motorola Droid and the upcoming Motorola Droid X. Both manufacturers use a custom version of the Andriod user interface with their devices, so it usually takes longer for users of these phones to receive the latest updates
The update will be compatible with most Android phones released in 2010. If you have an older Android smartphone, like the T-Mobile G1, don't expect to get Froyo, as its hardware is said to be too limited to provide full support.