Bradley Holt has a new post to his blog today talking about the experience he's had with testing the PHP 5.4 alpha1 release, just posted from the PHP development group.
Rasmus Lerdorf today posted instructions for testing the upcoming PHP 5.4 release. Running the PHP tests and submitting the associated report will help the PHP team get PHP 5.4 ready faster as it gives them reports of failed tests from a variety of platforms. I just did this today for the first time and can tell you that it is very easy. Following are the steps that Rasmus outlined, in a bit more detail.
He lists a few things you'll need before you get started and where to grab this latest code from. He describes the make/make test process and what you might see if one of the tests fail. You can find the results of the failed test submissions on the Test Reports page.