Spoilers, I guess, but the movie is out on home video and frankly you should be supporting good films in theaters:
With Caesar uttering most of a sentence at the end of Rise of the Planet of the Apes, will the simians speak more in the sequel? This is the dilemma facing Rick Jaffa and Amanda Silver, who are at work on the sequel script. While being interviewed on the Jeff Goldsmith podcast, they had this to say about further monkey talk:
We’re working on the sequel right now, to the prequel, and so the excitement is – I’m not gonna tell you, but – are they gonna talk or not? Part of the challenge was how to get across what was happening between the apes without words. In the end I think it was a good challenge for us. It created better storytelling.
I want the apes to talk, but as an old school Apes fanatic, I was always troubled by the fact that the mute slaves of Conquest of the Planet of the Apes ended up learning grammar and spelling in Battle for the Planet of the Apes. This should, realistically, be a slow process, and I don't mind them taking it slowly.
That said, Caesar should definitely be talking in the sequel.