@@DrXann
I only hoped, that some older characters would appear on screen. Given, that a lot of things have been revised, there was a chance, that everything including aliens would have changed since Episode VI. The early revealed pictures gave the impression, that the team wanted to hide any aliens from us, so any screen you see has humans for the most part.
I am glad, that we see Sullustans and Mon Kalamari, because it's a signal, that the new film won't re-write any of the older species, but more like adding new aliens to Star Wars, as in Episode VII new and old ones will be seen side by side.
I still wonder, whether we will see some Neimodians in the background or maybe Jawas some time later (Episode IX maybe).
In the video above a few shots suggest, that the Rebels (Republic) are operating from their former base on Yavin IV (look at the walls and computers).
According to SWU, another character is now revealed - General Hux, which serves the Empire (First Order).