Looks like Keira Knightley and Abigail Spencer have now entered the mix. I'm a big Abigail Spencer fan, in particular, and would love to see her finally blow up. I doubt she's a big enough name, though...
http://deadline.com/2014/09/true-detective-colin-farrell-vince-vaughn-justin-lin-confirmed-season-2-hbo-839632/
http://deadline.com/2014/09/true-detective-colin-farrell-vince-vaughn-justin-lin-confirmed-season-2-hbo-839632/