Probably one of the most important security-related tools, used on a daily basis by many people, has been updated. The new OpenSSH 4.0 has been released a few days ago.
Among the usual bugfixes are also some nifty new features. IMHO a very nice thing is the new (optional) hashing of host names and addresses added to known_hosts files. This improves your privacy, as the list of hosts you connected to in the past, is not easily visible in plain-text anymore.