We already grow our own breast tissue.
I would say a lot is possible, but they need to first start growing more common things like hearts and transplanting the grown hearts into people. We are a very small minority so we will be a low priority as a result. Maybe in 50 years we'll be able to get more advanced procedures, but I'm not going to count on it since I think its WAY to far off. I think a working womb is more likely than working testies. The reason being is that most people have at least one "X" chromosome which is the female chromosome. So I would imagine the genetic instructions for making a womb are in there. The instructions for testies on the other hand are probably in the "Y" chromosome which is much more limited since only men are supposed to have one.
The reality is that genetic rule that "XX"=genetic women and "XY"= genetic man as far as your body is concerned doesn't always hold true. In addition to "XY" can still be female (without them knowing about it) and "XX" can be male (super, super rare as some of the "Y" information has to cross over to your father's "X"), there is also XXY, XXXY, XXYY, etc... But 99% of people are either going to be either "normal" "XX" or "XY". If you assume a 50/50 split between genetic males and females, this means that the "Y" is limited. However I suppose its possible to get someone else's "Y" and trade it with one of your "X"'s while leaving everything else the same in order to fix that. I again suspect this is 50+ years off.
