Like in "Being John Malkovitch", so you'd literally be seeing what they're doing and (kinda) have some control? I think it's only possible in the movies my dear, but only time will show us...

The sheer complexity of the human brain and the inherent lack of regeneration and plasticity attributes of the mature nervous system mean it is very unlikely to occur, to the point of basically being impossible to trasnplant a brain from one body to another. The brain is not like a heart or kidney that is connected by several large 'tubes' - e.g. the renal artery and vein and is relatively easily removed. The brain is connected to the rest of the body by an immensely intricate system of neural tissue, with a great number of nerve bundles only the thickness of toothbrush bristles (i.e. very delicate). Since the brain is responsible for the manintenance of nearly every vital function, each single nerve fibre would have to be matched perfectly and then connected and healed, currently, this is impossible to feasibly accomplish and in my opinion not likely to be ever accomplished without major damage. And of course, the ethics of this are another major obstacle to be overcome. Finally, since we don't really know the full physiological and anatomical systems that grant us each of our, for want of a better word, personalities, chnaces are, if the ethical issues were dealt with, and if we could connect every single nerve fibre to its corresponding one in the recipient body, and if we could then somehow cause the nerves to regernate and grow together, and if the person was still alive at the end of such a drastic procedure, there is no way of saying whether the person wold retain the original personality, memories, mental abilities etc, or whether the person no longer resembles the original. And this is all assuming the person doesn't suffer a severe emotional and mental breakdown from the trauma of getting a full body transplant anyway.

Sorry if my question wasn't that detailed, but I was on about the mind and not the actual brain which is physical. Have you seen that science fiction film about "body-hoppiing"? I think the film was called Xchange.