Of course, it could be a form of damage reduction, go back to page 10/11 and read all the hate about the pricing, if they release the DLC in the US at a much lower price, the european fan community will be outraged, if they release it at the same price as in europe, they face a backlash from the american community, it's a lose-lose situation.
A less likely situation is that they just forgot about them, if we just send SCEA LOADS of e-mails asking for the pulse DLC to be relased in america, maybe somthing will happen.

LotL: Laughing out terribly loud

@jklasdf: Couple of years ago, stayed near St Thomas, Really freindly people round there, in fact, the whole of Ontario was nice and freindly...