And really, I'm not entirely shocked that a Twitter-owned service is getting more sharing on Twitter compared with a service that gets a reasonable amount of obstruction from Twitter.
That doesn't mean people will riot if it isn't available on their device. If you've got Android 2.x and can't get Vine, you likely don't really care as you haven't ever used Vine.
Are people really likely to get in an uproar over Vine?
Facebook, Twitter, Instagram, sure... but Vine?