Teddy bears are actually all over the console COD games. In Finest Hour you could pick up a Teddy bear for a little extra health. In Call Of Duty 2, you "killed" a teddy bear in Russian training mission. In Call Of Duty 4, there where various teddy bears used as misc. set peices. They're not hard to find. I think the Teddy bear symbolizes that Infinity Ward won't try to change the winning formula to much.