Microsoft‘s release of the Windows Phone 7.8 Software Developer Kit (SDK) should make it a little easier for developers who are looking to test drive their apps and the Live Tiles of those applications with the updated OS.
Not surprisingly, Windows Phone 7.8 is largely a cosmetic update, maintaining backwards compatibility with WP7 and WP7.5 apps while providing a few new features and a new look and feel for users. The new OS update supports resizable Live Tiles like Windows Phone 8, but includes the same APIs as the Windows Phone 7.5 SDK. This, of course, is a good thing, meaning the legacy apps and emulator images will still work perfectly in the newly-tweaked environment.
Microsoft has included additional information about this release on the Windows Phone Developer Blog.