Was thinking that, but what to put behind the wall?
get sued for copyright infringement might be a good way
A movie or tv name doesn't get trademarked though and I think that is the real difference.
You're joking, right? Of course movie and tv show names are trademarked, not to mention character names, etc., etc.
Insert foot in mouth - TV series names are usually trademarked, but single use film titles are not.
That being said, if you are posting content related to the movie - including stills, etc. that could very well be copyright protected and that would be enough for them to go after you.
I did this exact same thing with the Grand Theft Auto IV game. I bought the domain for it about a year before the release and would post updates, screen-shots and rumors about it. It ranked really well for most of the major keywords.Start building content now. News, pics, tidbits, whatever. Put a WP blog on it and just write at least one post a week. By the time the movie comes out you should have some decent aging on the domain and content indexed. Also build up links slowly over time and then blitz them when the movie comes out.
Then you can monetize however you want, CPA offers, AdSense, Direct Advertisers, whatever works for you.
I did this exact same thing with the Grand Theft Auto IV game. I bought the domain for it about a year before the release and would post updates, screen-shots and rumors about it. It ranked really well for most of the major keywords.