Mustardseed Media are a company that do programming (mostly of church websites) and teaching/consulting on the Drupal platform. Their video podcast has a high production value, a good resource!

I was at the Toronto Drupal users think-tank meeting Nov 2008 to hear Daniel Zivkovic of Jasmina Homes speak about the latest news on everything SEO.

http://acquia.com/

This is their enterprise corporate package, the install is free but they offer professional tech support and site monitoring and other added support to Drupal programmers