How will Halo 3: ODST have a co-op campaign, when the trailers say that you are...

[ravi]

...alone? Bungie tells us that in the new Halo you will be alone, they also say that the campaign will be four player co-op, how can this be? Please respond!!

 

[Zombafied MLG]

It will be like Halo: CE and Halo 2 where when two or more people played they were all one person. So my guess is that there will be you and three other ODST's that all look the same.