The hardest thing about being a Star Wars fan in my opinion is the unreliable nature of Lucas. He’s constantly changing his story and effectively retconning explanations for things.
Yes, I’m dead certain he once said he’d like to do a full 9 piece series after the old trilogy had been made. During the prequels I remembering him saying in interviews that he didn’t really see how he could do that, for the complications of his aging and that of the cast of the original trilogy at the very least. He said that he had grown to like the idea of leaving it at 6 pieces, with a central theme of Anakin’s fall to darkness, and eventual redemption (through his own actions and that of his children).
Besides, the EU did a fantastic job of covering the next 25 years or so of galactic “history.” I don’t really know where he’d go with it, unless he picked one of the trilogies (preferably Zahn’s Dark Force Rising books) and adapted it.
Incidentally, if you don’t know what the EU did, and don’t mind spoilers…
[SPOILER]basically they operated from the assumption that the galaxy is a big place, so even though the Battle of Endor was a key decisive victory, like the Normandy landings in some respect it was just the beginning of a much longer campaign against the Imperial loyalists (or perhaps Gettysburg might be a better example?). There was an extended period of back-and-forth fighting until the New Republic had pushed the loyalists back into a corner of the Galaxy where the population had a genuine majority in favor of remaining Imperial. They made peace, just in time for the NR to get embroiled in political infighting and face a deadly new invader from the outer reaches. With the Imperialists help, they were able to push out the new aliens (the Yuuzhan Vong, a name which always makes me think of Viet Cong).
During this time Luke has founded a new order of Jedi by training pupils in an academy environment. He’s had a few students gone bad, but for the most part it’s been a big success. The new Jedi really live up to the prophecy of balancing the Force because they’re goody two-shoes as always, but nowhere near as cold and logical as the old order. They have families, they have emotions, they’re people.
I don’t really know what all they’ve been up to since, but I gather it involves Jacen, one of Han and Leia’s kids starting down the path of the Dark Side, and the rebirth of the Mandalorians (an ancient nomadic tribe of warriors, often at odds with the Jedi, from whom Boba Fett is decended and from which his armor comes), which Boba Fett (who escaped the Sarlacc monster, though it took an extended period of illegal cloning-based medical treatments for him to recover; there’s some speculation it effectively made him younger, too) now leads. While Fett and Solo have set aside their grudge, it’ll likely start anew since Jacen is implicated in the death of Fett’s daughter. [/SPOILER]