There's a possibility that this is real. True, Bin Ladens ideology is different from Saddams and they don't like each other, but Osama might still suggest an Iraqi link to Al Qaeda... What Bin Laden wants is a global jihad, a ww3 if you will and it could be possible that he's trying to escalate the situation into this. So while there doesn't even have to be a link (which I think there isn't), he might still release something like that to advance his cause.
