Henrik Sjökvist: The benefits of centralized contrib hosting
I've recently been saying that one big advantage Drupal and WordPress have over Joomla is the centralized hosting of "third party" contributions (plugins/extensions/modules). Yes, Joomla has the extensions directory, but come actually downloading the software, you get directed to the individual developer's island website to do the download (where you might actually need to first register, are likely to needing to do some digging to find the actual download, etc.).