Ok, so here is my fan cast, given an unlimited budget, good prevailing winds and a proper alignment of the planets.

Director(yes, I even thought about this): Joss Whedon
Producer: J.J. Abrams (Moar lenseflare)
Screen Play: Jim Butcher

Harry: Nathan Fillion (For his delivery, I know he doesn't have the perfect look, but the other actors I considered as Harry don't have the presence to carry a movie)
Murphy: Elizabeth Banks  http://images.dailyradar.com/media/uploads/showhype/photos_large/2008/09/15/tn2_elizabeth_banks_4.jpg
Bob: (Depending on what we're going for with the movie) Hugh Laurie's voice (for a darker film), Alan Tudyk (lighter, more action-comedy style)
Thomas: Sean Maher
Molly:
The Archive: Elle Fanning (Dakota's all grown up, time for Elle to take up the mantle of playing creepy ethereal children.
Michael: Eric Bana (lighten his hair a bit)   http://laughinggasonline.files.wordpress.com/2009/07/eric-bana.jpg
Gerald Butler  http://trobentica.blog.siol.net/files/2008/11/gerardbutler.jpg
http://littlejunkies.files.wordpress.com/2009/09/gerard-butler.jpg
Paul Bettany  http://topazbean.files.wordpress.com/2009/08/bettany-chaucer.jpg
Charity Carpenter: Laura Linney
Ebenezar McCoy: Sean Connery or Gene Hackman
Marcone: Robert Downey Jr.
Morgan: Anthony Hopkins (Circa 10 Years ago) or Liam Neeson
Lara Raith: Angelina Jolie
Carlos Ramirez: Jon Huertas
Susan: Cote De Pablo
Butters: Brian Dietzen (already played an ME)
Johnny Galecki (adorkable)
John Francis Daley
T.J. Thyne
Mortimer Linquist (because it's my fancast): Nicholas Brendon
Lasciel/Lash: Scarlett Johansson
Nicodemus: Hugh Laurie (if not bob)
Christian Bale (I don't like him at all, but he did restrained crazy well)
Paul Bettany (if not Michael)
Simon Baker
Lea: Cate Blanchette
Summer Queen: Nicole Kidman
Justine: Dakota Fanning
Maeve: Christina Ricci
Toot-Toot: Anton Yelchin

All I've got for now.
LLAP