MARK HAMILL'S RETURN?
Because of real-life tragedy and narrative choices in previous films, Mark Hamill is the only member of the original trilogy's main trio who can appear in Episode IX. Since the trilogy finale is also set to close out the Skywalker saga as a whole, many expect Luke to be back in some capacity. Hamill (who would be content to stay on the sidelines) has said he'd play Luke again if that's what Abrams wants. And he's already teasing some ideas.
Luke would have to be a Force ghost in Episode IX, but it might be time to do something new with the concept. Hamill has discussed the possibility of playing a "frightening" spirit, which could be fun. Luke's final words to Kylo Ren, "See you around, kid," read as some kind of final taunt, so Luke could haunt his nephew as Kylo struggles leading the First Order. It'll be interesting to see if Lucasfilm confirms Hamill's involvement when Episode IX begins production, or if they leave it up in the air until the premiere.
A TIME JUMP IS A POSSIBILITY
The Last Jedi broke franchise tradition by picking up just moments after The Force Awakens. Previously, there was a gap of at least a year (usually more) between saga episodes. Given everything that's happened, it'd be very difficult to do that for Episode IX. Even if Fisher were still alive, a time jump would read as the smart choice, allowing ample time in-universe for the Resistance to build up its forces and the First Order to adjust under Kylo Ren's rule.
John Boyega hinted that a sizable gap was in order when he said he was growing out his hair in preparation for reprising his role as Finn. In movies, few things represent the passage of time more than changing a character's physical appearance. The only question is how many years after Last Jedi will Star Wars 9 take place. The franchise has a habit of dropping viewers in the middle of the story, so we expect the all-out war to already be well underway.
REY AND FINN SHOULD BE TOGETHER AGAIN
One of the biggest reasons why The Force Awakens worked so well was the chemistry between Boyega and Daisy Ridley. Through their adventure, they sold audiences on Rey and Finn's burgeoning friendship. The two didn't share much screen time in The Last Jedi, save for a cathartic embrace on Crait near the very end of the film. For those who like watching the youngsters play off each other, Episode IX could be your movie.
While at Awesome Con in 2018, Boyega revealed he received a text from Ridley that simply stated, "OMG we're together again." That makes it sound like Rey and Finn will by each other's sides for most of Star Wars 9. Since this is probably the last hurrah for the sequel trilogy's new guard (at least for a while), this is a smart move on Abrams' part.
STAR WARS 9 CASTING CHARACTER CODENAMED MARA
Every Star Wars film introduces new faces to the canon, and Episode IX won't be any different. It remains to be seen who is cast in any new roles, but there are some rumors about new characters. The first domino to fall was someone referred to as Mara, which makes fans instantly think of Mara Jade, Luke's wife in the old Expanded Universe (which is now dubbed Legends). However, the odds of Episode IX bringing Mara Jade to the official timeline are slim.
In all likelihood, this supposed character would (sadly) be some kind of Leia replacement (in the sense she's an older member of the rebellion who aids the youngsters), as she's described as a women aged between 40-50. Poe Dameron has cemented himself as one of the Resistance's leaders, but he can't do it all on his own. After taking heavy losses in The Last Jedi, the heroes will need some reinforcements, and more generals or admirals never hurts.
STAR WARS 9 CASTING NEW FEMALE LEAD
"Mara" isn't the only newcomer Star Wars 9 is looking to add. A separate casting call detailed a character referred to as "Caro," who is between 18-26 years old. The preference is for an African-American actress to play her, but no names have been connected to the role. Among Caro's traits are leadership abilities, problem solving, and a sense of humor. It is unknown if she would be aligned with the Resistance or the First Order. Both sides could use some extra help (Snoke and Phasma are gone), so it'll be interesting to see what happens.
Mara makes some sense, as she could be a supporting character who factors into one of the subplots. The inclusion of Caro is quite curious, since the sequel trilogy seems to have an abundance of young leads already. Ridley, Boyega, Oscar Isaac, Adam Driver, and Kelly Marie Tran are all more than capable of headlining Episode IX and handling action sequences. There doesn't seem to be room for someone else on-paper, but we're willing to give Abrams the benefit of the doubt for now.