OrientDB 2.0-M1 (milestone 1) has been released! According to the announcement from Luca Garulli at Orient Technologies, the big changes in this version focus on performance upgrades and user experience. For example, Studio 2.0 has a new feature called "Graph Editor," which looks pretty slick:
Beyond that, the biggest changes will be found in ETL (the OETL command tool) and a new documentation system. OrientDB's announcement provides a full list of changes, though.
Keep in mind that this is the first milestone, so you probably don't want to use this version in production. The final version should be coming at the end of the month.