I've been making themes that I'm going to sell in the Trading Post. I just realized that I've been instinctively creating search and contact form elements for the theme. Once the Trading Post is up, I think it would be cool to allow for the inclusion of Raven/Bloodhound licenses for purchasable themes.
e.g. "Buy this theme for $50. The theme designer suggests adding Raven: [x] Buy Raven ($49). Total = $99".