I'm not really much for long posts so I'll try and make this brief. Anchorhead once said that Lucas shrank the Star Wars universe by connecting characters together when they didn't need to be - for example, did Lando really need to own the Falcon before Han? Not really. I've been thinking about this, and he really has a point. Most of my examples will be PT ones, but just to start off:
-Anakin building 3PO. Unneeded connection.
-Count Dooku being Qui-Gon's master. Sure, it's a nice reminder that the only interesting character from the previous movie is gone, but is it needed? Certainly not. He could/should have been any regular old rogue Jedi.
-Anakin being raised on Tatooine. Perhaps not so bad, but he could have been found ANYWHERE in the vast Star Wars universe. He was there no reason other than Lucas's "poetry in motion" and the fact that it was already a popular, well-established locale that people would enjoy revisiting.
-Luke and Leia being siblings. The quality of the plot device is debatable, but there's no doubt that it shrank the universe. Characters that were once from completely different worlds basically came from the same one, even if they didn't get raised in it.
I'm sure there are more examples, but I'm a little tired and this is all I got tonight. Any other thoughts? Disagreements?