ElasticSearch 0.13.1 released with one major change, upgrading the Lucene version from 3.0.2 to 3.0.3. The new Lucene version fixes two important bugs, the first is a memory leak that happens when running a long indexing session, and the second is (very rare) index corruption.
I also backported some fixed bugs from master. The issues fixed are tagged with v0.13.1 here: https://github.com/elasticsearch/elasticsearch/issues/closed.
This version can coexists with 0.13.0 in the same cluster, allowing for a rolling upgrade option.