Left 4 Dead 2 may become the second Xbox 360 game to support Avatar Awards, should snippets of code in the game’s demo found by a Steam forum member prove accurate. Next to listing achievements and revealing that Gabe Newell will be doing developer commentary, the file lists the following items.

Med Kit: Earned by beating all five campaigns.
Bull Shifters Shirt: earned by winning 10 games of Versus.
A Left 4 Dead 2 shirt: Earned by winning 10 games of Scavenge.
Zombie Hand Shirt: Earned by killing 10,000 Infected.
Depeche Mode Shirt: Earned by rescuing Gnome Chompski from the Dark Carnival.

‘Splosion Man got its unlockable Avatar clothing just a few days ago. The beginning of a trend, perhaps?