I agree that big items would have to be truly iconic like the Falcon for Hasbro to take any kind of risk putting it on store shelves. Now, the Falcon is the least amount of risk they could do...and they will get a good return on it, you have people like me who really don't collect anymore who will be looking for this!
Other vehicles that Hasbro could consider:
-AT-AT (perhaps) -- They re-released the updated vintage mold so much, and it did relatively well each time that it might be worth a gamble.
-Turbo Tank -- If these make a big appearance in the Clone Wars cartoons I could see one being produced, otherwise I doubt it.
-Star Destroyer -- If they did a "new Falcon" type of thing with a Star Destroyer it might work and some retooling of a design could give us PT and OT versions, but it's a bit of a stretch.
-Sail Barge -- Doubt it...I know many collectors want it, but it was in less than 10 minutes of one movie.
As far as playsets, again for Hasbro to take a risk on these you would have to use something iconic and the Death Star is truly the only one that comes to mind. I'll agree that the POTF2 versions that they came out with were crap, so Hasbro would have to do something big, that has an equal amount of play/diorama value. Sorry Sal, but some of the way you were describing playsets were more of a diorama heavy idea and I can't see Hasbro doing those but I could see:
-Cantina playset (hell the vintage one was great, an updated version with perhaps sound effects of the cantina theme, lightsaber and blaster fire as well as some of the lines would be possible)
-Star Destroyer -- it might work as a playset if the vehicle idea doesn't...only because the Star Destroyer is almost as iconic as the Falcon.