Yeah they teased this at Comicon, but the main official trailer just came out and I wanted to share it. Having read the book I can tell you thus:
The plot is more or less a standard "Race to follow the clues to some grand treasure" plot like, say, National Treasure or DaVinci Code. Except instead of being specific forms of history, all the clues are related to 80's Pop Culture. Add in the fact it takes place in a virtual world and you see ALL THE REFERENCES. The book included references to things like Dungeons and Dragons, Gojira, Adventure, Tempest, Wargames, Monty Python, and many many more.
Now, obviously they can't include ALL the references because it would be a rights nightmare (From what I heard, the Iron Giant appearing in the movie is likely replacing a giant robot from a somewhat obscure Japanese animated show), but it'll be interesting to see what they DO manage to get right.