Granted, yes, the reasons are keeping the audience interested for that still far off December U.S. release, but there isn't much new to gleam here that any previous trailer didn't already give us. Still, lots to admire in mood, cinematography and production design. Not to mention the music.
If you'd like to get a further sense of Inside Llewyn Davis, than you can read Ryland's review of the film from Cannes right here.