With the new update, users will be able to leave video messages for friends who don't answer when you try to call them on video chat. Video messages will be able to be up to three minutes long.
The update will also be coming to Mac, but oddly, there is no update coming for Windows just yet, so Windows 8 and Windows Phone users will have to wait a bit.
When the update does go live, you'll be able to grab it for free in the iTunes App Store, and the Google Play Store.
source: Venture Beat