I was reading on the wiki that during the course of the story the US Military forms a unit called the "Ghosts" lead by a "Retired Army Captain". Sound familiar to anybody? A certain series by Ubisoft? I.E. Ghost Recon? Did the developers of CoD think about this? Is this enough of an infringement of names and story to promote a lawsuit against CoD by Ubisoft? Just a thought.

I'm quite certain Activision's army of lawyers is in contact with Ubisoft's army of lawyers. As a general rule, companies pay tons of money to tons of lawyers to check this sort of stuff before shipping.

You still gotta admit, the similarities are too close to call here. 

...unless they, say, reached a deal with Ubisoft. As a general rule, companies let other companies use trademarks for sufficient sums of money. There may well not be a legal case, and any case would almost certainly be settled (instead of a court ruling on it, the two sides agree to certain conditions, generally involving a payment from one side to the other and the condition that neither can reveal how much the payment is, and then drop the suits). The odds that this actually goes to court for a legal ruling are low.

All that is out there; feel free to make me eat these words if I'm wrong.

As cp702 said, I'm sure that the Activision's lawyers reviewed the story to make sure there were no copyright infringements. Plus just because something is similar doesn't mean Ubisoft can win a lawsuit against Activision, as I'm sure the team of lawyers changed the story just enough to avoid infringement, assuming it ever did infringe.