Quote - Breasts, being semi-fluid, are going to be problematic as long as they are not simulated in a physics engine of some sort, like dynamic hair and clothing.  To do it properly, the breasts would have to be dynamic, a ribcage structure would have to be defined, and they would have to be able to be contained and re-shaped by clothing as well as gravity.

Agreed. My vote goes to the Tit Room, expected to appear in Poser 12 or so.