Hot on the heels of some international bug squashing events the next iteration in stability for 1.5 has been released codenamed karibu, to quote from joomla.org
"Just a week and a half ago people from all over the globe gathered in various locations to do a little Bug Squashing… today the fruits of their labour can be revealed as we announce the release of Joomla! 1.5 RC4. This release is code named Karibu which is Swahili for nearby, close, close by, at hand… all terms that we feel reflect the nature of this release.
Karibu marks an important milestone in 1.5’s development, as barring any major issues we believe it will be the last release candidate, with the next release being the big one… Joomla! 1.5 stable. When that happens will in part be influenced by the Joomla! community…
More so than any previous, this release really has been one of unprecedented community involvement with people from all the various Working Groups as well as others banding together to help increase momentum as we head for a stable release. There is an enormous amount of energy building up around the 1.5 release and it is inspirational being a part of the process."