PHPKitchen.com has this large list of PHP CMSes posted today with reviews for each.

The list includes such "household names" as Mambo, Drupal, and Geeklog as well as a few comparison articles, like Mambo Vs Everyone.

Also included are a few others that he couldn't find reviews for, but are notable none the less (such as binarycloud, phrame, and Bitflux).

Wrap it all up with a few "various links" and it makes for a very informative post...