Arc System Works has confirmed it is going to be releasing Guilty Gear Xrd: Rev 2 later this year for PC, PS4, and PS3. Before those releases the game will be out in Japanese arcades first. This isn’t a huge sequel however and more like an update, similar to the jump from Street Fighter IV to Super Street Fighter IV. Two new playable characters are being added, Baiken and Answer, along with additional story content and better online support.
If you already own Guilty Gear Xrd: Revelator then there will be an upgrade option to get the new content, instead of having to buy Rev 2 standalone. A price for the upgrade has yet to be announced as does a release date.