Why have they posted the ad already? Where did you find that out?
Its better than the first one, but its kinda the same thing. Theres some other modes I guess and new weapons and new infected. It is "better" though. I am definitely not paying $40+ for it. Basically, valve said, "no lets not add this to l4d1, lets release an entire new game and charge another $40-$50" heh.
This type of game gets insanely repetitive and losses appeal for many. With that said, I never bought l4d1 so I figured id buy this second one.