Today we released version 4.2.1 of Apache Solr and Lucene. See http://lucene.apache.org/solr/solrnews.html for the release announcement.

This is mostly a bugfix release over 4.2, including such things as Collections API fixes, SolrCloud replication fixes and more.

If you missed the 4.2 release, the major news was that stored fields are now compressed by default, meaning you could get a significantly smaller index footprint if you store a lot of fields.