The PyCon announcement reminds me of what may be the biggest difference between Python and Ruby:  if you speak at a Ruby conference, your registration fee (and often other expenses) is waived in gratitude for your effort.  If you speak at a Python conference, you pay full price in recognition of the privilege you have (to market yourself or something).

I have very strong opinions on this, but anyone else interested might want to read the links and comment thread at Marty Haught's post: 
http://martyhaught.com/articles/2011/06/07/conference-organizing-and-speakers/

Ben Brumfield
http://manuscripttranscription.blogspot.com/