EA's Tokyo press conference today, Valve's Kim Swift announced intentions to release a demo on October 27. Though no platforms were explicitly mentioned, we're betting pre-orders on both Xbox 360 and PC platforms will be getting first dibs, as Valve has already stated.
From what we understand, the demo will feature multiplayer, though we're not sure to what capacity this will extend. Either way, Xbox 360 and PC owners will get a chance to try out at least some of the 10 melee weapons well before the game's November 17 release. We'll ask EA for more details on the demo as the Tokyo Game Show continues this week.