If there has been a recurring gripe with Vine, it's that you've had to capture all your videos in Vine to share them -- you either had to record 6-second square clips or head elsewhere. You won't have to make that compromise any more, though. As of today, iOS users (Android is coming soon) can use existing videos in their Vines, no matter how many are needed or how they were shot. If you want to stitch together highlights from your iPhone 5s' slow-motion footage, you can.
You'll have also more control, whether or not you're content to shoot inside the app. The Vine camera now lets you duplicate and mute clips. You can also use a "ghost" mode to line up with a previous shot, and a torch feature lets you make movies in pitch darkness. The additions might diminish the spirit of Vine's simple, on-the-spot recording, but they could also lead to more professional-looking clips that keep you (and hopefully, your followers) coming back.