Sorry to go against almost everyone who has posted so far, but this image looks terrible and does not make the film look promising. I know it is just one still of the creature running, but it is obvious it is CG. I know it is impossible to make CG stuff look completely realistic (no matter how much James Cameron believes he can) but filmmakers can integrate CG against real footage better than this. Hell, I believed the Transformers were real more than I do this.
The Host is good on its own anyway, why make a sequel. The same goes for The Descent.