We expect Apple to demo and distribute a new, nearly-final build of Snow Leopard to developers, and at least announce a ship date for iPhone OS 3.0. It will be nice if we get a firm release date for Snow Leopard and a preview of new iPhone hardware, but we aren't holding our breath. Stay tuned to TUAW during the show for coverage and reaction to everything from WWDC.
Of course, I wouldn't be a nit-picky jerk if I didn't mention that a year is a measure of time while a light year is a measure of distance. I wonder if the new iPhone will make the Kessel Run in less than 12 parsecs.