I second Bruce Campbell! He lives right outside Grants Pass, if I'm not mistaken.
Some people I'd like to see:
Yoko Kanno - I don't know how hard it would be to get her, and according to Wikipedia she speaks very little English, but her music is SO AMAZING.
Doc Hammer (Eric Arthur Hammer) and Jackson Publick (Christopher McCulloch) - Most famous for The Venture Bros. They've made multiple con appearances before, and though they're not really anime, they're still awesome.
Guillermo del Toro - Amazing filmmaker. He's the genius behind Pan's Labyrinth, as well as Hellboy and Hellboy II. He lives in California, but he was just announced as the director for The Hobbit (YES!), so he's moving to New Zealand, and I don't know if he'd be in the states around K-con time. Still, if he could come, it would be absolutely fantastic.