In this new post to his blog till argues his case for PEAR and why support for PHP4 is a good thing when it comes to making things "just work."
Every once in someone likes to argue that PEAR is all fugly PHP4 code and why you should not use it, and instead go and use another framework or component library. Most of those people also say that they looked at or used PEAR x years ago and then act all surprised when someone else disagrees.
He talks about some of the rules around the major/minor PEAR releases and backwards compatibility breaks which, thankfully, a lot of other projects seem to adhere to. He points out that some packages have been started for different PHP generations (Mail_Queue2 vs Mail_Queue) and a few reasons why the PHP4 EON doesn't automatically mean PEAR should follow suit.