First let me say that I love your covers! I don't think you've ever made a set that I didn't think was fantastic.
Secondly, I was wondering if you took suggestions and/or requests. Looking at the Prequel covers above I had an idea for something else you could do with them. You have a pic of Qui-Gon Jinn and Obi-Wan vs. Darth Maul on the Ep. I cover and you have a pic of Anakin vs. Obi-Wan on the Ep. III cover. What if you put a pic of Anakin and Obi-Wan vs. Count Dooku on the Ep. II cover? They would all tie together that way, and as it is I think the Ep. II is just a little bit more bland then the other covers. You could even carry the lightsaber duels idea into the OT. You could have a pic of Obi-Wan vs. Darth Vader for Ep. IV, a pic of Luke vs. Dath Vader for Ep. V, and a pic of Luke vs. Darth Vader in front of the Emperor for Ep. VI. Just an idea.
The other thing that would be cool to see is the gradual fade of the color you did for the OT covers done for the PT covers. I liked your OT covers best, and I think that was part of the reason why. Like I said, I would like to see it if you could make 'em, but I understand if you don't like to do requests or you're just too busy right now.
Finally, just want to encourage you to keep doing what you're doing. Your work is simply terrific!