Rumors have been circling non-stop since the first announcement of Episode VII, so if I posted every single one of them I would have to be typing 24/7. But, I just thought I'd to a quick overview.
Apparently the original cast (of the prequel trilogy) will be in the movie, but I would much rather have them be supporting characters than be the main action heroes. If I wanted to see old people go on adventures, I would just watch Up again.
If the trilogy is going to be about Luke/Mara's and Leia/Han's children, then I just hope that it takes place when the kids are at least in their teens, because I don't want to see little kids. It'll be just like in Jurassic Park when the little kids just scream and hide the whole time, which would be fine except they didn't get killed in the end.
Rumors have been circling about when the next trilogy will be taking place. Some people are saying it should be in the Old Republic, but I don't think they'll do that. Besides, they already have probably about one-movie worth of animated clips for all of the previews for the Old Republic game. Those were really awesome, but I think we'd all like something new.
Some other people are saying it should take place between episodes III and IV. That is...a terrible idea. First of all, there isn't a ton that goes on during that time, and the few interesting things that do happen were already created in comic books or video games or something (I'm referring to the Force Unleashed video games by the way).
Second of all, (this reason works against the Old Republic too), it's already confusing enough between the prequel trilogy and the original trilogy, because people who are listing the movies in order say that A Phantom Menace is Episode 1, but people who want to stay true to the original order in which they were made (mostly old people) would call A New Hope Episode 1. So, if the next trilogy took place in-between episode III and IV, we would have the Prequels, Original Trilogy, and Post-Prequels-but-Pre-Originals Trilogy. That's really confusing.
Various topics for the next trilogy could include:
1. Destroying the remnants of the Empire. There are many different Expanded Universe books that they could take ideas from, but I think that they want to have an original story.
2. The Yuuzhan Vong invasion. Again, this idea is from books or comic books, so they may not want to use it.
3. An entirely new idea that we probably couldn't comprehend.
Thinking of a substantial idea that could make three new movies will be hard. You might say, "Well, they've done it twice before," but they've actually only done it once. After Episode VI, they had a whole bucketful of ideas and themes that they could make more movies about, including:
1. The destruction of the Jedi.
2. How Anakin Skywalker became evil.
3. How Luke and Leia's parents met/fell in love.
4. Obi-Wan's relationship with Anakin.
5. The creation of the Empire!
So in reality, they only made completely original ideas for a trilogy once, and that was 40 years ago when writers and directors DIDN'T completely steal, rip-off, and recycle other ideas.
Only time will tell when the real details of the new trilogy will emerge...