Reports of more Muslims calling the cover offensive, the very fact that a caricature was made an insult to religion. Settle down there, and think.
From what it's been interpreted to me, Mohammed didn't want to be worshipped, didn't want anyone to be praying to icons of him instead of the god he was speaking for (atheist, not important here). So it's not "make no images of me", it's "don't worship me" and icons were something used for that.
Since I doubt anyone is going to worship this cover, seems there's no problem. From that interpretation, I can understand why he might weep, over those that felt that he should be above reproach, that they should kill in his name, when he's "just a man doing a duty".