Drush is (at least from my experience) not that well documented. The commands seem to change slightly with every version
I did figure out how to download themes with drush.
sudo drush dl sky
downloaded the sky theme
But I couldn’t figure out how to switch to that theme using drush so I just switched to the new theme via Appearance in the Drupal admin. In any case here’s Drupal with the Sky theme:
http://librarymonk.zapto.org/drupal
