It looks like Scarlett Johansson will assume the role previously earmarked for Angelina Jolie in the 3D sci-fi flick Gravity.  NY Daily News [via Bleeding Cool] reports that Johannson has "verbally agreed" to star opposite Robert Downey Jr. in the film.  Directed by Alfonso Cuarón (Children of Men), Gravity follows "a woman as she attempts to make her way back to earth after a satellite crash sets off a chain reaction of further crashes."

Much of what we have heard about Gravity has more to do with the tech than the narrative: Cuarón is reportedly touting the CG-heavy film as "the most ambitious film, technology-wise, since Avatar," and it is rumored that the opening scene is a single twenty-minute take.  More Gravity details after the break:

The visual effects company Framestore is working on the film, and at one point posted a wealth of information on their website.  It has been taken down, but here's an excerpt from The Playlist:

The entire film will be made here at Framestore. In effect the film, as Avatar was, is 60% CG feature animation with the balance being hybrid CG and live action elements.

Starring Robert Downey Junior, the film is a contemporary survival thriller that follows a woman as she attempts to make her way back to earth after a satellite crash sets off a chain reaction of further crashes. Because it's set in space, most shots require every element to float in zero-gravity.

But then factor in that this is a stylish Cuarón flick, directed with his trademark languid feel, and you begin to realise the full scale of our challenge. Cuarón's long and fluid style (the opening shot alone is slated to last at least 20 minutes) leaves no cut points to hide behind. In short, this is a hybrid of a fully animated, photo-real feature film with a blockbusting visual effects movie.

It all sounds very ambitious, and we may be in store for something special if Cuarón & Co. can pull it off.  (And really, is there anyone you'd rather have at the helm for such a project?)  Gravity is scheduled to start shooting later this summer with a 2012 release in mind.