Soem of the names I'm most excited about are:
* John Clute. The premier critic of SF&F literature. Co-editor of several encyclopedias, critic, and author. One of the finest minds in the field
* Ellen Datlow. Editor of Scifi.com's Scifiction, and numerous anthologies. A very influential editor, who publishes some of my favorite authors.
* Terry Pratchett. Need I say more?
* Mike Resnick. A very talented author, and appears to be an incredibly nice man from my brief correspondence with him.
* Robert Silverberg. He wrote "Nightwings." He wrote "Enter A Soldier. Later: Enter Another." Even if he hadn't written anything else (and he wrote a LOT. Much of it good, some of it great, some of it really not so great), those two would be enough to put him in the pantheon.
* Kim Stanley Robinson. Red, Green, Blue: Mars.
* Cory Doctorow. Haven't read much of his SF, but the guy is SHARP. Also, he's the main reason I read BoingBoing.
Not to say I'm not excited to meet some of the others named. But those are pretty damn big for me.