@Silence:
It'd be pretty shocking if he could make lightning strike not twice, but four more times.
Thats what people said about Avatar following up Titanic. "Sure, the movie with a boat was the biggest success ever, but no way he matches that."
[hide]
The story of Avatar may have sucked, but the action and visuals and things he did to appeal to the widest audience possible are all there. Cameron is a smart film maker, he knows how to get an audience.
As for no one talking about the film now? Of course not, it was six years ago. No one talks about The Matrix or Men in Black either unless it comes up. (Or to grab other films of that year, Inglorius Basterds, The Hangover, Zombieland, Watchmen, Coroline,District 9, Where the Wild Things Are, The Human Centipede. How many of these get brought up except when compared to genre or a director's past work?)
There's been no cartoon or tv series or line of books to keep people invested, so of course it doesn't come up. We're a more discriminating crowd because we see a lot of fantasy stories and aren't impressed by pure CG so the fact that the story and characters were bad grates on us, and will keep some of us out of the theatres the second time, but it was liked by a huge general audience. You don't get to that B.O. purely on the tech or people being curious, those numbers only come from people seeing it two, three, five times, and dragging their friends along.
When the time finally comes for the movies to come out, they'll start showing trailers a year in advance and spend 200 million on advertising and they'll remind people then that it exists and its a thing and it will get a large audience to go see it for the spectacle, same as the Transformers movies and Superman.
I can't imagine it doing anywhere near as well the second time, because the total numbers were boosted by the 3D curiosity and all, yes, but it wasn't everything. It has an audience, it will again. Some disgruntled folks that didn't like the first won't go back (like myself) … but some people that hated the first one will still go and see it anyway, look at how many people here went to see BvS despite knowing they'd hate it and the reviews. Just so they could see it for themselves and then decry how much they hated it.
Movies don't even advertise that they're 3D anymore, the fad came and went and now its just a standard feature... but you can bet that one they'll advertise "shot especially for the 3D its really the only way to see it because we know other movies have been shit for 10 years but its really totally amazing on this one." and get some of that back again. And if anyone says "for those that didn't care for how formulaic the first one is... this one eschews the Dances with Wolves parallel and tells it's own story,a nd as a result is far better than the first" and that'll get suckers in too. "I didn't care for the first, but this one is better... I guess I can give it another shot."
Sight unseen with nothing but Cameron's track record to go on and how much the first one made, I can't imagine it making less than a billion dollars. If it's a complete and total dud, and gets 20% on Rotten tomatoes, it might top out at only 800 million, but that's the absolute bare minimum it makes. If its even remotely passable it'll do good. Now if its a complete dud, and the third one is a complete dud, then the BO on the last might suffer, but... as long as its reasonable escapism with some good action scenes and state of the art effects, it'll get people in for the theatre showings. People may not remember or care about what they see afterward, but they'll go see it.
Twice, because the action was so good.[/hide]
tl:dr
I can't imagine it being as successful as the first for a lot of reasons… but its still gonna make a crapload of money.