The Asterisk.org development team has published Asterisk version 1.6.0-beta1. Everyone is encouraged to help test Asterisk 1.6, so that the release may be available soon. Asterisk 1.6 will be the first major release of Asterisk since 1.4, which was released just over one year ago. This release contains a number of new features, as well as architectural improvements for improved performance. A list of the new features is available in the CHANGES file:

There has been a thread on the Asterisk-users mailing list about the various opinions about upgrading Asterisk versions. I spent some time reflecting on the differences over time between Asterisk 1.0, 1.2, and now, 1.4, and posted my thoughts to the thread. The List Archives