Maybe it's inevitable that performance capture will one day be recognized as an awardable achievement, but probably not any time soon, probably not against non-digital actors, and most probably not by the Academy.
Slashfilm wrote a feature on this Rise of the Planet of the Apes campaign for consideration:
No matter how excellent a performance an actor gives (and Serkis's is very excellent) character animators have the ability, and often do make subtle (or not subtle) changes in the performance. How could an awarding body compare digitally altered or created performances to those that aren't?
We've all seen the companion arguments brought about by performance capture. Full chimp make up, full nose make up, computer generated tears, and these Alice in Wonderland screen tests (skip to 0:20 and pay close attention to Alice at 1:20) all raise the question of what is and isn't performance capture. And the questions are no closer to being solved this year by Cesar and his pals.
All this to say, I don't believe for a second that Fox expects Andy Serkis to be nominated. The Academy went through this same issue with Serkis in a more heavily "acted" role, for a movie much more in the Oscar spotlight, Return of the King. But if you want to get awards buzz for your film, a controversial topic like this that gets blogged and reblogged is going to bring a lot more attention than your typical consideration spreads. Kudos for that, I suppose.