Thought and played little bit more than I should have with Drupal7 and Joomla. Some observation. It is very difficult to create web sites with Drupal7 and Joomla. It might be useful to a corporations but creating a simple website is a royal pain.
I further evaluated some Wiki software which could be used as CMS. Came down to two Tiki Wiki (monolitic written in PHP) and Foswiki (a free fork of TWiki) modular written in Perl.
I really like Foswiki and that would be my personal choice now. These are serious websites built with Foswiki
http://tig.csail.mit.edu/wiki/TIG/
http://articulab.hcii.cs.cmu.edu/foswiki/
http://www.cs.rpi.edu/
http://bioinformatics.cesb.uky.edu/
I learned way too much about this shit. Far more than I ever wanted to learn.