Damien Seguy has posted the PHP statistics for this past month, August 2007:

Here are the PHP stats for August 2007. To learn about methodology, read la section phpversion. 27.1 millions servers hosted on 2.4 millions IP were surveyed during August, and 11.8 were used for stats : domaines without web sites, those unreachable, ISP, shared hosters or domain parkings were not considered.

Highlights this month include:

• The start of the decline of PHP4 usage!
• PHP 5 break its progression record : +1,5% to 22%
• August 2007, best month to compile PHP

Check out the full stats here with the evolution stats here.