We have several new Drupal 7 sites:
This one uses the Danland theme:
http://nullifynow.net/
These use the AT Adaptive theme
http://amend-it.org/
http://grand-jury.org/
http://redistrict.org/
http://sortition.net/
http://trial-jury.org/
http://lancasterian.org/
I wanted to go with an HTML5 theme, but after trying the ones available, I found all but AT Adaptive to have disagreeable things about them that drove me to adopt AT Adaptive for all of them. I had hopes for Omega but kept getting errors. Sky didn't display lists properly. Genesis was too barren and clunky looking without doing a lot more work than I cared to do.
These sites are at an early stage of development, so visit again to see what I have added to them.
I am looking forward to being able to use CiviCRM and SubGroups in Drupal7, but the SubGroups authors say they have no plans to do the port from 6 to 7, so it may be up to us.