Races: human, elf, dwarf, ork and troll
Roles: Street Samurai, Mage, Shaman, Rigger, Decker. Possibly more post release
Oh and they have posted a primer about Shadowrun (more about the setting of Shadowrun and not the upcoming game, so nothing new if you are already pretty familiar with the PnP game)
http://harebrained-schemes.com/shadowrun/primer/
Game play wise as I understand it the game will be 2d turn based (similar to the old snes game or the UFO series)