I've updated and expanded the slides which I presented at DrupalCon 2010 San Francisco.
I'm now including some preliminary stats for Django (a python based framework), and at the request of @easement (Michael Billings) ground out stats on global variable use in Drupal releases from 4.6 through 7x.
Update: Antoine Beaupré (anarcat) kindly pointed out to me that my LoC slide for Drupal releases was pointing at the wrong numbers (off by one error in indexing!). This is now updated. I'm also posting the spreadsheet itself.
Another update:Mikey_p just pointed me to some metrics he has been working on which look at rate of features being added to Drupal 7: check out http://skitch.com/mikeyp/n9ke2/skitched-20100417-101751