'Hamill recalled that while making Return of the Jedi, he was absolutely sure it was the end of the series, “because we had a beginning, middle and an end.” But during that period, George Lucas did talk to him about his bigger ideas for a series of trilogies – initially four different trilogies, and then three. Still, said Hamill, “I don’t even think I believed that the third trilogy would feature us. I thought it would be all different characters. To my knowledge, we were just going to do a beginning, a middle and an end [in the original trilogy] and it was over."'
Hamill also talked a little about Episode VII:
"While talking about how much he loved filming the Dagobah sequences for The Empire Strikes Back, which were shot on a soundstage with a lot of practical effects, Hamill then made his most specific mention of his involvement in Episode VII, revealing, “I’ve only had one creative meeting about the new films, but I do remember saying, ‘We’ve got to find a proper balance between CGI and old school [FX].”
The Jedi then explained more about what this could mean:
“That’s what the challenge is, is to try and meet expectations of what you guys want. I think there’s nothing wrong with CGI, but I think you have to have a balance, because the camera perceives the width and the depth and the weight – even if it’s a miniature model, the camera just realizes that. So when you have too much CGI and the clouds are CGI and the trees are CGI and the buildings are CGI, you’re getting to a point where the figure in the shot is like a hybrid of an animated film and live-action. And I want it to have an organic look so that we don’t get into Roger Rabbit territory."