As most of you might have seen we recently announced the first alpha of PHP 5.3.0. The major changes are listed in the announcement. Source tarballs can be found on PHP's downloads site, as it's the first release I packaged I'm especially interested in feedback, whether it works or not :-). But we didn't only have changes on the source builds: A new team took over the creation of Windows builds. As they also did a major update to the Windows build architecture (supporting newer compiler versions on Windows and added experimental support for 64bit platforms) the build process got a bit delayed but builds should be available soon.
Remember: It's a release we packaged to get feedback from our users. So please test it. If you find issues please report them - the sooner we know about issues the sooner they can be addressed. Although our test coverage increased we can't cover all cases in our tests so please test it now and don't wait for the stable release, once the stable release is out your edge case might trigger a bug on a productive system, bugs reported now can be fixed before we release a final version.
If you want to give back to the PHP project - hey you probably make a living out of software you get for free - and can't fix bugs or assist in a similar way you probably could help our documentation team with improving the documentation, there are a few features without proper documentation, yet.