In a new post to his blog, Sebastian Bergmann mentions a new effort he's undertaken - the porting of the Hamcrest library of matcher objects to PHP.
I have begun to port Hamcrest, which provides a library of matcher objects (also known as constraints or predicates) allowing "match" rules to be defined declaratively, to be used in other frameworks. Typical scenarios include testing frameworks, mocking libraries and UI validation rules, to PHP.
The hamcrest-php project compliments other current hamcrest-related projects and his ultimate goal is to make it available to the PHPUnit testing community (as well as with the PHPMock effort).