Argo had the unstoppable momentum in a lot of categories last year, Best Adapted Screenplay especially. This year, there isn't a single film with an unstoppable momentum outside of animation. The guild awards split up a lot of the winning films and that makes this anyone's to win really.
It seems silly to me that Before Midnight is in Best Adapted, but I guess it counts as material based on the earlier films. It's just so rare to see sequels that aren't based on best selling sci-fi novels or comic books (as in, something that can really get nominated). It's gotten plenty of accolades for its screenplay, but for me, it's more of an actor's movie, less of a writer's movie. That may just be biased because the actors (and director) wrote it, but all of the little touches that made it a worthwhile film were actorly touches.
Of course 12 Years a Slave was also an actors' film, but doesn't carry the same bias as it was written by John Ridley. However, John Ridley's involvement is a bit of a hurdle to overcome in the voting. During the Writer's Guild strike of yore, Ridley crossed the picket line. Needless to say, he upset a lot of fellow writers in doing so. (You'll note, that 12 Years a Slave was not nominated for a WGA Award this year. It's because Ridley wasn't eligible.) Final balloting is voted on by the entire 6,000+ member body (a lot of whom were already on the other side of the picket line), so it may not end up being as big a deal at the Oscars as it was with the WGA Awards, but it's an issue worth noting either way.
Philomena was really the surprise nomination out of all of them for me. Who really expects a Steve Coogan nomination for anything? He's brilliant of course, but he's low key and usually flies under the radar. But then again, who doesn't love a Stephen Frears film? And Philomena is certainly worth loving.
Captain Phillips and The Wolf of Wall Street shared the same problem for me: they were both too much at once. It worked in stretches in The Wolf of Wall Street, but surely not for all three hours. The Lemmons scene really saves the whole film. Captain Phillips started out so strong but got lost in that rescue sub and real life controversy along the way.
12 Years a Slave – John Ridley [Read the PDF]
Before Midnight – Richard Linklater, Julie Delpy, and Ethan Hawke [Read the PDF]
Captain Phillips – Billy Ray
Philomena – Steve Coogan and Jeff Pope [Read the PDF]
The Wolf of Wall Street – Terence Winter [Read the PDF]
12 Years a Slave, and it's not even really a contest in my mind. It's unfortunate for the film that John Ridley crossed the line, but he knew at the time it would have repercussions and this may or may not be it.