Given that the parent comment says this is being integrated into Symfony2 (if I read it right), it seems strange to introduce another config format to handle it

Given that the parent comment says this is being integrated into Symfony2 (if I read it right), it seems strange to introduce another config format to handle it. As if a mixture of PHP arrays, YML, annotated comments and XML wasn't quite confusing enough. Not that I have a problem with JSON itself. It's my serialisation format of choice in PHP as the extra verbosity of its native serialisation seems unnecessary given the lenience of the language.