First off, this is a great feature Scott...I look forward to reading each update. I agree with what has already been said, this Chewie (actually, both the EB and VOTC versions) is one of the best figures Hasbro has ever done. I also consider this one "finished", and don't see how it can be improved on. Just keep carding this Chewie until the end of the line, and I'd be just fine with that. I'd also like to see the EB version get released on a vintage card, perhaps to finish out one of the upcoming waves. Other than that, I think with the various paint variations (Hoth, etc.) on this one already, there isn't much more to do with Chewie than continue to get this figure out there on a somewhat regular basis. Definitely a "definitive" figure in my book.
Chewbacca was one of my favorite action figures as a kid, and continues to be today. I say just keep using this definitive wookiee sculpt just as they did in the original line, it doesn't get much better, as Jesse said.