I think it would be awesome if Valve released an update (optional) where the Day of Defeat engine would turn from the hl2 engine into the Left 4 Dead engine, the animations would be amazing!, They would have to put a few edits to it though, such as the addition to prone. BUt would be awesome 
Btw, i dont mean like zombies, and l4d weapons etc... just the engine.

Btw, i dont mean like zombies, and l4d weapons etc... just the engine.






















