Vine now supports higher-resolution 720p video as viewed from the Android app, with video uploads for that same resolution coming soon for those users.
Vine announced the new higher-resolution videos in a blog post, adding that they will be viewable on both their iOS and Android apps "over the coming days". Vine video posts made from the iPhone can already support the new 720p format, and videos with this new higher resolution can be viewed on the web. From Vine:
For those with an Android device: rest assured, you'll soon be able to create and upload posts with the same quality as well.
It doesn't appear that you need to download an update to see the new 720p videos on the Android version of the app, though you should probably update it to the latest version from the Google Play Store.