I was listening to a science program this morning that was discussing growing replacement human organs from the patient's cells, and it wouldn't have to be the liver cells regrowing a new liver, it could for example be skin cells tricked into believing they were now liver cells. In theory it would get around the rejection issue. Using the same logic it stands to reason that, with a tickle of the chromosomes from X to Y (or vice versa), that the cells might be tricked into creating reproductive organs of the opposite gender for the patient (and not be biologically rejected when attached). I agree though that the wiring of the brain, and over coming the fact that it has developed to deal with the original set might prove problematic. The brain is fairly elastic though and might therefore grow new neurones over time to cope. Franken-science is so much fun to speculate with!
I did hear about a guy who received a hand transplant. The operation itself was a success but he rejected it psychologically... looking at it and using it freaked him out too much and they had to cut it off. Some people can cope with that kind of transplant (and some have had full face transplants) but others not so much, even if they really want/need it.
I have a F2M friend. When he first outed himself to me, although I was happy for him I felt it was a shame there wasn't a way we could just swap bodies (before he started on T, obviously!) I'd have his short, very cute girly body and he'd have my towering, meh guy body. Don't know if we would have then assumed each others identities or what. Mind you, even if we were both very happy with that arrangement, I don't know if his boyfriend would have been!