I have a lot of hopeful feelings due to that teaser.
(And I'm again impressed with how well Lucasfilm keeps its cards close to the vest: the title didn't leak, images didn't get out, and a Major Revelation that the teaser reveals had only been hinted at through rumors: and remember there'd been rumors that Jar-Jar Binks would be in The Last Jedi, so rumors here are definitely not necessarily reliable.)
I don't know enough to say much. That's by design: I want to be surprised by this movie, as much as possible. (I managed not to learn too much about any of the recent Star Wars films before seeing them.) I'm kind of thinking around the film: were there ever earlier plans to bring Billy Dee Williams's Lando back in this trilogy before now? Is that desert on a planet we've seen before? Exactly how did they build Leia's part in this around the footage they had of Carrie Fisher from before? How much if any of the Episode IX ideas Colin Trevorrow worked on made it into the final film?
But again, my main feeling is, aptly, hope. The people who make Star Wars really, truly want to stick this landing and end this part of Star Wars in a way that honors the series's weird, wonderful legacy, and also sets up where Star Wars goes from here.
The Phantom Menace. Attack of the Clones. Revenge of the Sith. A New Hope. The Empire Strikes Back. Return of the Jedi. The Force Awakens. The Last Jedi. The Rise of Skywalker. Today is the first day we can list every numbered episode title. The galaxy far, far away can still, I'm glad to say, surprise us.