On the official site the current question asks if Lucas has any ideas for Episodes 7 8 9. The answer is no. Lucas says that the Skywalker family story ends with the destruction of the 2nd Death Star. I guess we are to assume that Luke and Leia rebuild the Jedi Order and the Republic. I guess we can start using the EU as the rule rather than the exception, well maybe not but it gives it more creedance.
Oh, I see. Yeah I think he's now left it wide open for the EU but with TNJO and the way things have progressed in novels at least I guess they'll keep moving forward rather than returning to post ROTJ events again.