We have an update coming soon.
Cool!
Hopefully she won't arrive just in time for the late-night Voice Actors Uncensored panel this time...which was an epic panel, btw.
I actually didn't get anything signed by her last year @ Matsuri as Saturday and Sunday didn't work for her autographs with me. 2 cool guest panels or waiting in a late-starting queue for Brina on Sunday; which would you choose?

Were there any other guests on the flier who aren't yet listed on the Matsuricon web site?

I don't remember any other names that jumped out at me when I saw the flyer. Probably should've actually taken one with me rather than just look at it. My group of Soul Eater cosplay friends and I are very excited to see Micah Solusod, and my fiance got extra pumped when she saw Brina on the flyer, since we love her work too, most notably her roles in Negima!? and Shin Chan.
It'll be our first Matsuricon!