This is a bit different to the Reader scenario. They're not shutting down Google Groups, they've shut down one particular group, without explanation. I think the symfony community would be happy if we could just get to the data to move.
Composer (getcomposer.org) and Packagist (packagist.org) are largely a popular replacement for PEAR, though once you need a C extension (PECL), you're right, it does become a pain.