He's still got to make it alien swarm friendly, but its kinda proof that people are out there making maps and stuff for this game!
Has anyone tried playing this First person mode yet btw? Don't know the commands, but a quick search in the alien swarm source steam forum should get you the commands you need. Must admit, it looks pretty spiffing even in that view, specically if you want to spice it up/make it harder and tense