James Sie, the original voice of the cabbage merchant in the animated series, also plays the cabbage merchant in two episodes of the live action adaptation.
The creators of the original animated series, Michael Dante DiMartino and Bryan Konietzko, were originally hired as executive producers and showrunners. Unfortunately, the pair felt that Netflix did not follow through on their promise to support their vision for this retelling and decided to leave the project.
Daniel Dae Kim previously did an episode of the original animated series, voicing General Fong in the season two episode, 'The Avatar State' He also did seven episodes of The Legend of Korra, voicing Hiroshi Sato.
Seasons 2 and 3 are expected to be filmed back to back. Most likely to combat the rapid maturing of the younger cast members.
In season 1, episode 2 the scene where the trio are on Kyoshi Island and Aang is riding on his air ball around then smacking into the statue is a reference to the original series intro.