For me the most interesting line is
"We customize Open Source software we use
- often improvements are not sent back
– many are gross Y!-specific hacks"
Will Yahoo! start acting like a good open-source neighbor? If they start giving back to the community that could be a real boost to PHP. If not, it becomes an interesting bit of internet trivia, much like the stories I heard about them doing custom work to get Oracle to play well with Free-BSD. I have no idea if it was true, but there was a time when it would have been real handy to have learned from their experiences. The Free-BSD community would have really benefited from a heavy hitter like Yahoo being more than just users of other peoples work.