I highly doubt it. If it was in his plan, it would have to be after ROTJ. GL even stated in an interview recently in Premiere magazine that there were a lot of gaps he had to fill, seeing as though he said everyone was expecting the PT to all be about Anakin's fall, and according to him, Episode 1 was about "a 10 year old boy", Episode 2 was a "love story"...(if that was its main drive, you totally failed at it)....and then he realized he had to cram everything left into Episode 3, thus he made up quite a few things last minute such as 3PO's memory being erased.
In all fairness, if you were smart you would have made the Episode 1 be about them meeting Anakin in the Clone Wars, like it was originally (he was already a great pilot, not a great pod racer) 2, be about the clone wars and the fall of the republic, the rise of the empire, end with anakin's fall, then episode 3 be about him being darth vader, killing the remaining jedi, and take more time on all that, instead of cramming it all into the 3rd one, so really I think that Episode 3 is the one I've been waiting for. If you ask me, I could totally forget the first two.