The problem is that playing as the survivors isn't for everyone and the only videos they have released are for the survivor side. As a survivor you are forced to work with your team and try to offset reloading so that you don't get swarmed. Its all about working as a single cohesive unit or you will die a horrible death. It is that cooperation aspect that makes the game interesting to me, you can't just be that one excellent FPS player and dominate the game because you have to reload eventually and when you do you will be overwhelmed and eaten alive...literally. Working with your team and calling out when you spot zombies, letting people know you are reloading, watching each other's backs etc.. are all things that really wrap you up into the role and immerse you into the game.
Now the zombie side seems like it will have more selection for the different play styles, particularly if the rumor that they are adding in more boss infected is true. The ability to climb just about anything, go smashing through walls to terrify the survivors as you pound them into the ground, rip someone off the street from the rooftops, and all of the other abilities the zombies have is what makes the game sound truly amazing and takes it to the next level for me.
For anyone who can't see what is so special about the game, please follow the links Ben provided to left4dead411.com and read their hands on information. If you read that and still don't see anything special then maybe there really isn't something for you here, but I think most people will find something that gets them at least a little hyped up.








