During this interview for LIVING IN THE AGE OF AIRPLANES, which held its premiere aboard an Emirates Airbus A380 inflight (!), James Horner was asked about what he's working on in addition to this film and he confirmed he is indeed scoring the AVATAR sequel, though he said it's quite a ways away obviously.
I actually consider it Horner's opus magnum. He's never been better!
The amusing thing isn't that someone thinks that Avatar is something special - I enjoy it myself - but the idea that said person's opinion is some sort of empirical data is...
Well, I'll let you Mad Lib the last word or two after that ellipsis.