From the announcement:
This is a significant release of Fedora that includes a complete repackaging of the Fedora source and binary distribution so that Fedora can now be installed as a standalone web application (.war) in any web container. This is a first step in positioning Fedora to fit within a standard "enterprise system" environment. A new installer application makes it easy to setup and run Fedora. Fedora now uses Servlet Filters for authentication. To support digital object integrity, the Fedora repository can now be configured to calculate and store checksums for datastream content. This can be done globally, or on selected datastreams. The Fedora API also provides the ability to check content integrity based on checksums. The RDF-based Resource Index has been tuned for better performance. Also, a new high-performing triplestore, backed by Postgres, has been developed that can be plugged into the Resource Index. Fedora contains many other enhancements and bug fixes.