For those that are into shipping, on one of the Book 1 DVDs, (I think it is Volume 2), Bryan and Michael were asked about if Zuko and Katara would get together, and if Aang and Katara would get together.
When asked about Zuko and Katara, they didn't answer the question seriously, joking about Momo and Appa getting together.
When asked about Aang and Katara, they said we all have to watch the show and find out.
What does those completely different style of answers tell you, which is more likely to happen?
Maybe they were taking a back about a Zuko and Katara question, because that that is their intention all along, and changed the subject quickly. Or their thought was, Zuko and Katara, are you serious? No way.