With a $450M worldwide gross, it’s a no brainer that RISE OF THE PLANET OF THE APES was going to get a sequel, even if the end did seem rather conclusive.
Even with good looking humans James Franco and Freida Pinto in the headlining roles, it’s obvious which star absolutely must return for a new film. That would be Ceaser himself, Andy Serkis, who has just closed a deal to reprise his role as the ape. It may be all CGI, but the lead monkey could not exist without him, and the studio realizes that and are reportedly paying him quite a sum to return.
As for Franco and Pinto, their fates are unknown, but with the way the last film ended, it wouldn’t surprise me if their return wasn’t necessary.
There has been brief discussion about the plot of a sequel, centered on apes building their own society as the world burns, but yeah, it’s a tough sell that creatively this reboot needs a follow-up. But who makes movies for creative reasons anymore?