I just ran into someone from WB walking through the office carrying this thing... Naturally, I pounced. :cool Turns out it's a promotional one that the studio made as a show-off piece. They made a few of them (at a cost of about $300 each I was told), and appears to be a fairly accurate duplicate of the original(s) (although I've never seen the original in person, so can't say that for sure). I'm not sure if WB is holding on to all of these, or if they might be given/sold to people at some point, but it's something to watch out for. (Also something to be careful of if someone is ever selling a 'screen used' one...)
The bottom of the box had the name of the movie and a copyright line or two printed on it, so it's easy to spot as a replica (although I suppose that could be removed).
Unfortunately I wasn't able to takes pics/measurements... :rolleyes
[Edit] Reading back through the thread I see that someone mentioned the studio is giving away replicas in various contests... That must be what this was. It did look pretty good, possibly built by the same people using the same techniques as the original...
Looking at the sweepstakes rules, it appears there was one grand-prize winner, and a couple of 2nd-place winners. All the websites seemed to advertising the same contest (at least, I think that's what they were doing...), so there might just be one box so far that the studio gave away (but they did make at least a couple of them).