I think a lot of things could be referenced from the PT - doesn't mean they will though.
If things start up in sort of a civil war (whether beginning middle or end), you can have references to 'the last time', 'why should we trust the jedi, they blew it before', establishing the seat of the new republic on corscuant, seeing the jedi temple (or not), finding old ships/data/etc....there are plenty of ways to reference it. Doesn't mean you're flashing back or etching any but broad strokes, but still. The story of the PT wasn't bad, but the execution left a lot to be desired. Doesn't mean you shoot everything else flatly ignoring it - though you could. Depends on what the story calls for and i'd imagine whatever the story, it'll call for a little reference here and there.
I'm surprised that nobody has posted this already but the Chive.com has posted a bunch of leaked photos from the set of Ep. VII. Nothing ground breaking, just a bunch of extras on a desert world but it does show the sets, at least this one, are going to be largely practical.
Leaked Photos of Star Wars: Episode VII (25 Photos) : theCHIVE
Yeah the chest box is very Vader.
Wow, that's cool!
And I confirmed it in an earlier post 5 days ago.
I can tell you that the new Stormtroopers look really cool. Even though they have been updated, you know what they are the minute you see them.
The story of the PT wasn't bad, but the execution left a lot to be desired.
More good stuff from Kevin Smith and his set visit:
Kevin Smith Confirms Stormtroopers in Star Wars: Episode VII! - MakingStarWars.net
VERY COOL! Not sure if this has been discussed... Will Leia have a light saber?
Since my record is good so far, I also want to mention that I saw what I think is a Snowtrooper as well.
I wasn't going to mention it at all because I wasn't sure, but I just saw a main character's costume ( I can't tell you whom) that indicates there may be a snow or cold environment in the next film.
Damn. I was hoping to be Mr. 300 for this thread...