The director is interested, the producer (Scott) is interested...
I think Fox would be interested... If they want a new heroine for a sort of reboot, they already have Noomi Rapace on Prometheus, so I'd say there are really high chances.
The concept arts show a seasoned Ripley, so I think Blomkamp's pitch was that, and Fox apparently bought it. He said Alien and Aliens are their favorite movies of all time, so having Ripley would be the most logic thing in the universe.