Nick, I've still been hunting high and low to see if I can locate something to trade you for that Yoda, but as yet, I haven't run across anything interesting. If there's anything you're looking for, do let me know and I'll be on the lookout.

I'm genuinely excited to see what Unleashed figures ROTS generates. I'm hoping for a Wookiee ripping a Clone Trooper's arms out of his sockets, but I guess I'll just have to wait and see.
There is a maquette on page of 157 of the "Making of ROTS" book alongside some production art of the same situation that shows a Wookiee dismembering a Battle Droid, so maybe they will go off of that for a starting point.

It seems to me, however, that Hasbro is starting to reach the end of original ideas with a lot of the Unleashed stuff. To me, it's not a line that really lends itself to a lot of minor Cantina aliens or generic characters (with exceptions of course), and if the next wave that has been rumored to occur is true, it's going to be three versions of characters we already have (for the most part). If it's a generic Wookiee, that's okay, but another Chewbacca? And so soon after the last one?
Out of the main characters, the only ones left without an Unleashed figure are R2 and Threepio, Qui-Gon, and Lando. There are other characters that I'd like to see in UL form (a Biker Scout or Admiral Ackbar in hoverchair would be cool), but some of them I don't know how they could do them. For instance, I'd love all 6 bounty hunters, but how would you do a 4-LOM Unleashed?