I know this is really late and all, but how about Mon Marshall (known for various voices of Digimon, Musashi of Brave Fencer Musashi, and Toboe of Wolf's Rain to name a few) and Yoko Kanno again?
I don't think Otakon's ever had Mona before, but I'd definitely love to see Mona and Yoko Kanno on the guest list!