Last Updated: September 9th, 2014
Update: An update to the News & Weather app posted yesterday, September 8th, seems to have fixed some of the compatibility errors people have been seeing. At least here in the United States, the app is compatible with every Android 4.0+ device for all of our writers. There doesn't appear to be any other significant update just yet.
Google's News & Weather app, AKA the "Genie" widget (after the APK name), has been more or less unchanged for years.
Last Updated: August 21st, 2014
Update #1 (8/12/14): It looks like Google deleted the tweet embedded below. Between that and the lack of an update to this support page, someone might have pulled the trigger early. But if those countries don't have access yet, they probably will sometime soon.
Update #2 (8/19/14): After a false start last week, the Play Music expansion now seems to be live. The official Google Play country availability page has been updated to reflect this as well.