While I am glad to be rid of DADT, the new non-discrimination policy does not cover transgenders. So, while a gay man, lesbian or bisexual can't be discharged or denied enlistment or promotion (at least not officially, anyway) on the basis of his or her sexual orientation, transgenders can't remain in the Armed Forces. In fact, even expressing one's gender identity issues can keep a person who wants to enlist out of the Forces, and result in a discharge for someone who's already in. And "coming out" after leaving or retiring from military service--as Autumn Sandeen did--can cause problems in dealing with the Veterans Administration.
What makes changing the military's current ban on transgenders, or others with gender-identity "disorders", difficult is that the ban isn't a law. It's a mandate defined in the Defense Department's "Medical Standards for Appointment, Enlistment or Induction in the Military Service." (See p. 33, paragraph 3-35.) So it can't be ended by popular vote, or even a Congressional mandate. Only the Pentagon can change it, and it's a body that doesn't tend to be swayed much by public opinion. On the other hand, DADT was a Federal law and could, as such, be voted out of existence by Congress.
This isn't to say that the ban on transgender people won't be repealed. I just think that it's going to be difficult, in part because we're a much smaller community than lesbians, gay men or bisexuals, but also because doing so will require a change in the administrative culture of the Armed Forces. Having a President or other elected officials who favor such a change wouldn't hurt, but wouldn't, in and of itself, be enough.