PHP 5.2 has been a rather wild adventure. It’s all the way to Release Candidate 6. You can read more about it on Ilia’s Blog (release manager) and windows builds, including the very nice new msi installer, are available from Edin’s Blog (windows builds).
5.2 promises to be a leap forward, both in features and stability. It features a new filter extension, hooks for file progress uploads (which requires a seperate extension), lots of bugfixes, several bundled libraries updated including sqlite, and full __toString support.
If you have the opportunity, and a development box to play with, you should try installing the release candidate and make sure it doesn’t crash and burn horribly. And let’s hope the final release doesn’t require another RC because I’m looking forward to 5.2