The generation of the nightly builds has now been automated, so from now on we will have one nightly build each night. This should make it easier for folks involved in testing and debugging to grab the latest, bleeding-edge code. We do not recommend nightly builds for regular usage, so please do not use a nightly to power your main blog.
In other news, the version has been bumped up to 1.3-alpha-5, to reflect some of the improvements made in the past few days, which include lots of bug fixes, and some fine tuning of some of the administration related aspects, themes and the plugin API.
Kai, the maintainer of the WordPress debian package has come out with a debian package for WordPress 1.2.1. If you are a debian user please consider helping by testing the upgraded package as requested in the hackers mail linked to above.