Hi - This is James Thornton (espeed) from the Apache Tinkerpop project ( http://tinkerpop.incubator.apache.org/).
The Flink iterators should pair well with Gremlin's Graph Traversal Machine ( http://www.datastax.com/dev/blog/the-benefits-of-the-gremlin-graph-traversal-machine) -- it would be good to coordinate on creating an integration. Also, Apache Geode made a splash today on HN ( https://news.ycombinator.com/item?id=10596859) -- connecting Geode and Flink would be killer. Here's the Geode/Spark connector for refefference: https://github.com/apache/incubator-geode/tree/develop/gemfire-spark-connector - James