Reine and Kathryn I think you make an excellent point, because how we view this question and it's implications is contingent on our understanding of gender variance and it's degrees. Although we use the term gender identity I think we all know it's a lot more complex than just whether your switch is set to M or F, that's just a simple way of dealing with it for conversation's sake that only accurately describes a small segment of the entire population. I recently read this article by Bushong and he proposes a mesh theory of gender that although it is more complicated and doesn't provide easy labels I think it helps understand the situation better. By breaking down one's sense of individual gender into three categories it allows for a model that predicts what we see in the real world. If applied correctly I think it could be used by folks to help them decide how far they want to change their role towards their preferred gender role while balancing against the discomfort that is felt by folks who transition farther than perhaps they should have.
http://www.transgendercare.com/guida..._is_gender.htm