These screen size qualifiers have been deprecated beginning with Android 3.2 (HoneyComb). See best practices on Android developers site: http://developer.android.com/guide/practices/screens_support...
AFAIK, the density qualifiers are still being used, and are mentioned in the "new" design guidelines document as well, giving me the impression they may stick around for a while. http://developer.android.com/design/style/devices-displays.h...