Stinger and Stinger.next are both code names for work Hortonworks and the rest of the Hive community is doing. Stinger corresponds to Hive versions 0.11, 0.12, and 0.13. Those releases included Hive on Tez, Orc, vectorization and some very initial CBO work (as you noted). Stinger.next is just the next phase of work going on in Hive. 0.14 was already counted as being part of Stinger.next. It included transactions with insert, update, and delete and the first real delivery of the CBO. Hive 1.1 with Hive on Spark has also been released. Going forward there will be more performance improvements with the introduction of LLAP in a future version of Hive that we will count as part of Stinger.next.
Alan.