This might a stupid question but is this competing with Neo4j or Giraph? I didn't see a mention of comparison with either in the docs. I believe graph data storage and graph processing are two different things - is TItan doing both?
http://thinkaurelius.com/2013/05/13/educating-the-planet-wit... (cluster-sized graphs OLTP)
http://thinkaurelius.com/2012/11/11/faunus-provides-big-grap... (OLAP engine)
http://thinkaurelius.com/2013/11/24/boutique-graph-data-with... (single-machine sized graphs OLTP)