TID movie confirmed to be in early stages

This morning Martin Moszkowicz confirmed what we've all been hearing whispers of, that The Infernal Devices movie is in the early stages.  He confirmed a screenplay is in the works in a reply to a twitter user.

@mmoszkowicz Are they making a TID movie? It's another series by @cassieclare about Shadowhunters but from Victorian London Era.
— Tessa Gray (@WeBreathWords) March 25, 2013

@webreathwords @cassieclare we are working on the screenplay.
— Martin Moszkowicz (@mmoszkowicz) March 26, 2013

This is super exciting news, and now we officially have confirmation! Thank you @WeBreatheWords for asking!

Who have you fancast in your head?  Who is your Will, Jem, or Tessa?