My main concern is how the saga will be picked-up after it tied all the loose ends in Return Of The Jedi. It almost seems like an unnecessary continuation after the fall of the empire, the death of the Emperor, and no more Anakin/Vader who (say what you will about Luke/Leia), is the main character at the core of all 6 previous episodes.
Not saying the saga can't be picked back up & done well, but I find it hard to do so without feeling like a desperate plot push or cheesy direct-to-home-video style premise with so much wrapped up in ROTJ.
Here's hoping we're all in for a pleasant surprise from the galaxy far, far away.