He's been in everything from Firefly to Leverage, with Dollhouse, Warehouse 13 and Battlestar Galactica in between to name just a few. So why am I even surprised that Mark Sheppard has landed a big role in Doctor Who?

The news broke when Sheppard had to drop out of a convention appearance this weekend in order to start shooting; it's assumed that this means he'll be part of the two-part season opener that begins filming this week. Is it too much to ask that Sheppard's appearance will spur someone into coming up with a unified theory of nerddom chart?