Pull List; seems to be too long to fit in my sig...
How about Tower of Babel as a plot idea? Not that I desperatly want to see that either, but the central plot of an unknown threat using specific plans to take out each member of the JL and and the reveal that the plans originate from Batman is very solid IMO. It will allow the movie to focus on Batman (a safe bet considering his current popularity) as well as leave the story in a very interesting place for the inevitable follow-up with Batman thrown out of the League.
"Doesn't everyone on here hate comics? Isn't this a forum where a bunch of middle aged men sit around and bitch about how they hate comics and haven't read them in twenty years?" -Mezzaro-
Most people are aware of the Thanos teaser, either because they know the track record of the Marvel films, or through word of mouth. If they didn't stay in the theater, they saw it on DVD and Blu-Ray as well as Youtube.