The real problem with doing additional "post ROTJ" movies is that the books have carried that story SOOOO far along now that you'll have to go 100 years or more into the "future" in order to tell anything SIGNIFICANT to the existing characters or the galactic situation. Or else you have to say "well that entire expanded-universe thing we've been building up, with full continuity, for the past several decades... we're tossing all that out, so just forget about any of it." NOT GONNA HAPPEN.
FYI, I've enjoyed about 1/2 of the Expanded Universe books... which is actually pretty good. I didn't much care for the whole Yuzhon Vong series... it seemed like a whole series of stuff written just to be over-the-top-shocking without seeming particularly BELIEVABLE. And there were a few very weak "stand-alone" stories. But by and large, it's all been worthwhile. At this point, the SW universe has gone forward to the point where Luke Skywalker is getting old, his son is almost an adult and his wife (a former imperial agent) has been killed by Han and Leia's elder son, who ended up becoming a Sith Lord "to save the galaxy." In addition to him, they had two other kids... a younger son who was killed years earlier, and a twin daughter with the older son. There's a whole new Jedi Order, the galactic government has changed three times since the collapse of the Empire, and there's been another full civil war since then.
In other words... the stuff that's come since ROTJ has been MAJOR and FORMATIVE. And not the sort of thing that you can just dismiss unless you're going to toss every bit of all of it out. And there's not a whole lot of point in trying to tell those stories in the form of a movie.
Of course, there are now two "presents" in the EU. One is the one I mention above, and the other is set decades further down the line... but that allows for new stories to be told, I guess.
You could start off with a new series 100 years after ROTJ (since that period is still pretty poorly covered, with the main thing being that both the Jedi and the Imperial Knights have been hunted down and destroyed by the Sith Empire's warriors under the command of Darth Krayt, a former Tusken Jedi, with only a couple of Jedi still around, and the one we know about being Cade Skywalker, a descendent of Luke Skywalker who's given up his Jedi role and is now addicted to "death sticks." The future of that future is still undetermined, and there are other figures who could be dealt with, I s'pose.
