Until now, Android 2.1 is only available on the Nexus One, and this is only available in the USA. Now Google has already released the corresponding SDK, because Android 2.1 will sooner or later also be available for other devices like the Motorola Milestone or the HTC Hero - probably in spring.
Officially, Android 2.1 is only a minor update, but brings voice control for the entire phone and browser improvements (which are not known in detail, faster it should be). In addition there are animated wallpapers and more home screens than before (the latter could already be "fixed" with alternative firmware).
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