I concur... I'm trying to find a way to get in contact with the creator of smartmpreg.tumblr.com, I think he's the one who made that morph. He definitely been the most successful in depicting baby bumps on men, even so far as putting the linea nigra on the stomach. Hopefully we'll see more from him.
I think he takes real female bellies and "attaches" them on guys...which, anyway, isn't easy at all, because he has to find - or to recreate - a belly with the same colours!