Elasticsearch 2.1.0, released alongside a bug fix update for Elasticsearch 2.0.1, introduces several key enhancements based on Lucene 5.3.1, including the geo-centroid metric aggregation that offers a more precise overlay of geolocation data on maps, improving upon the previous row-and-column display. Three new pipeline aggregations are introduced to enhance the statistical processing of data, offering calculations like min, max, average, and specified percentiles. Further improvements to node restart times and shard rebalancing processes, such as synced flushing and delayed shard allocation, address previous flaws in shard management. Incremental changes include a soft limit on search results, default update behavior adjustments, and replacements for count and scan search types, aiming to optimize performance and user experience. Users are encouraged to download and test the new release, providing feedback via social media and GitHub.