The first release candidate for Solr 7.0 has been made, meaning we will probably see a release within days if no show stoppers pop up.
Solr 7 is a major version upgrade, featuring improvements such as:
New Solr versions are released quite frequently. Since we wrote about 4.7 back in March, we got Solr 4.8 on April 28th, 4.8.1 May 20th, 4.9.0 June 25th, 4.10.0 September 3rd, 4.10.1 September 29th, and 4.10.2 on October 31st.
The Apache Lucene project just released Apache Solr version 4.5. Please read the release announcement at http://lucene.apache.org/solr/solrnews.html#5-october-2013-apache-solr-45-available and see CHANGES.txt for all details. Some highlights are multi-threaded faceting (SOLR-2548), multi-threaded updates with CloudSolrServer (SOLR-4816) and more intelligent routing of documents with SolrCloud. Enjoy!