Down in Australia, blogger Zoe has posted an excellent summary of the medical evidence to date that points to underlying biological causes for transsexualism.
I continue to temper the optimism that some of this evidence will engender with the cautious view that the evidence is persuasive, but not at this point conclusive. What we have is a series of pointers that are leading us towards an understanding of a series of factors that appear to influence the emergence of transsexualism. However, we should also be just a little wary of falling into the trap of assuming that coincidence equals causality.
That said, I am very happy with the research work that has been done, and what that work is beginning to reveal.