As if directing four sequels wasn't going to be enough of a challenge, he's going to do them simultaneously. Of course, Cameron is making the endeavour sound like a breeze, saying it's just going to be like "one big production... the way you would shoot a miniseries." No biggie.
Speaking via Via, the director said: “So we’ll be shooting across all [AVATAR scripts] simultaneously. So Monday I might be doing a scene from Movie Four, and Tuesday I’m doing a scene from Movie One... e’re working across, essentially, eight hours of story. It’s going to be a big challenge to keep it all fixed in our minds, exactly where we are, across that story arc at any given point. It’s going to be probably the most challenging thing I’ve ever done. I’m sure the actors will be challenged by that as well. It’s like, ‘No, no, no, no, this person hasn’t died yet, so you’re still in this phase of your life.’ It’s a saga. It’s like doing all three GODFATHER films at the same time.””
As Uproxx points out: "But Francis Ford Coppola didn’t make all three Godfather movies at the same, and we still got The Godfather: Part III"...
Regarding going up against Star Wars - that's not going to happen: "My original plan was to release them a year apart, but we’re opening that up. If for no other reason than that I don’t want to land on the same date as one of the STAR WARS sequels. That wouldn’t be fair to them. [Laughs] No, that’s just good business. I don’t want to go head-to-head with STAR WARS. That would be stupid. And hopefully they won’t want to go head-to-head with us."