Free weekend of Left 4 Dead 2 for Silver Live members

Left 4 Dead 2 is going free on the Xbox 360 next weekend. Starting at 5pm GMT on the 15th until 5 on the 18th, Valve’s zombie survive-em-up will be free to play across Xbox Live. While co-op and multiplayer action is usually reserved for Xbox Live Gold members, next weekend anyone with an Xbox 360, a copy of the game and an internet connection will be able to join the baseball bat swinging, shotgun spraying, zombie face shooting fun.

Seriously though, you bought Left 4 Dead 2 without a Gold membership?