Valve sends word that those who have pre-purchased Left 4 Dead 2 via Steam may now pre-load the game demo, which is due to launch for early access on Tuesday, October 27. Early access to the L4D2 demo is available for both retail (360, PC) and Steam (PC) customers. Those who pre-ordered via participating retailers should be able to pick up their early access codes this weekend and be ready to play on Tuesday when the demo launches.