By the end of this year, James Cameron will have finished writing the scripts for both Avatar 2 and Avatar 3. As has been widely reported, these movies will then be filmed concurrently with the first one tentatively set for release in 2015. It's a risky strategy: plenty of other film franchises have attempted back-to-back sequel productions and, more often than not, at least one of those films has ended up being actively terrible.

Think Back to the Future 3, or the endless finale to the last Lord of the Rings film. Or Pirates of the Caribbean 3, so long and impenetrable that watching it feels like spending a month in a Chinese prison. Or either Matrix sequel, both of which could easily vie for the title of Worst Anything That Has Ever Existed. By taking on the Avatar sequels in this way, there's a very strong chance that one or both of them will be bloated, directionless and painfully self-important. And this is a sequel to Avatar we're talking about. Imagine something even more self-important than a two-and-a-half hour environmental lecture about a planet of lanky blue aliens with sexual haircuts. Petrifying, isn't it?

Luckily, it seems as if James Cameron has done his homework. In an interview with the LA Times this week, ostensibly about the 3D Titanic Blu-ray release, Cameron revealed the films that he doesn't want Avatar 2 and 3 to become. "I'm writing it as separate stories that have an overall arc inclusive of the first film. I don't want to suffer from the Matrix 2 problem, where it just ends, like, what the hell? It's gotta end. There's gotta be a sense of conclusion, but also a sense that the journey will continue, and that's a fine line."

That's sure to come as a relief to just about everyone. Although only a madman would use the Matrix sequels as a template for anything – apart from maybe a complex hope-destroying torture system – it's still nice to have verbal reassurance to the contrary. The sheer scale and pressure of following up a global blockbuster by writing, filming and editing two sequels concurrently must be enormous, and that's why so many of these films end up being monstrous, distended, throw-everything-at-the-wall train wrecks that sacrifice economy and focus for misguided spectacle.

But even with this in mind, the Matrix sequels were – and still are – heartbreaking. To create such a perfectly realised universe, and to break new technological ground, in the first film and then dump all over it with two separate movies full of hokey subplots and techno dance parties and symbolism that all but cracks you across the head with a cricket bat still seems like one of the worst fumbles in cinema history. No wonder so many people have taken to refusing that The Matrix Reloaded and The Matrix Revolutions even exist.

But at least James Cameron seems to know what he's up against here. Hopefully he's given himself enough time to pare down the scripts to an acceptable degree; to remove any mindless cliffhangers from the end of Avatar 2, to remove any extended car chase scenes and hard-to-follow kung fu scenes and techno parties, and any bits at the end where Sam Worthington literally becomes a blind version of Jesus Christ. Hopefully he'll avoid the same pitfalls that everyone else in his situation has plummeted into. Hopefully he'll manage to remember why people sort of liked Avatar in the first place. That's the best anyone can hope for.