The L4D mod uses Travis to meet the game's quota for one leather-clad survivor, putting him, in his usual red jacket and Pure White Lover Bizarre Jelly T-shirt (but no beam katana), in the place of ultra-pessimist Francis. While an L4D2 mod could address the lack of stabbing and cutting, it would seem mod creator ash_link isn't a fan of Valve's sequel, so, yeah ... that's probably not happening.
The Team Fortress 2 mod does about the same thing, replacing that game's Scout with a pint-sized, katana-wielding Touchdown. Head past the break to see for yourself. Seriously, go watch the video now.
Source - Travis Touchdown mod for Team Fortress 2
Source - Travis Touchdown mod for Left 4 Dead 2