Keeping the T in ENDA
I find the pragmatic rationale for dropping the T unconvincing. No ENDA will make it into law before January 2009, because either version would be vetoed by President Bush (assuming Republicans aren't able to use procedural tricks to kill it in Congress -- tricks which they'd use against either version), and neither version would have enough votes to override.
This year's ENDA fight is not a matter of pragmatic law-creation. It's a matter of clarifying where people stand and establishing the agenda, preparing the terms of debate for the day when the pragmatic battle is winnable. The version of ENDA that goes forward this year will set the standard or benchmark for the ENDA that is voted on in 2009.
Why, though, is it important for protection for trans people to be included in that benchmark? Many LGB people don't see why Ts don't have their own, separate movement. What does a gay man have in common with a straight cross-dresser?
The link between LGB and T is the grounds of discrimination against them. Homophobia and transphobia are both about resistance to non-conformity with gender norms. To the bigoted mind, being attracted to members of the same sex (that is, being attracted to the people that a member of the other sex should be attracted to) is just one among many forms of gender non-conformity. That's why lesbians are stereotyped as being extremely butch, and gay men are stereotyped as being highly effeminate. That's why bigoted parents will read a son's interest in (feminine) dance as a sign of gayness and enroll him in (masculine) little league as a corrective. It makes little sense to say that the fight for the right to be nonconformist in your choice of romantic partner should be separated from the fight for the right to be nonconformist in your way of dressing, choice of name and pronouns, chemical or surgical alteration of your body, etc. (And this is why feminism is at least a half-sibling to the LGBT movement, since resistance to gender nonconformity is a source of resistance to women's rights alongside resistance to the equal value of women qua ("normal") women.)
The gender nonconformity link also means that leaving the T out of ENDA creates a potential loophole for discrimination. Under the T-less ENDA, you can't fire someone for who they want to date, but you can fire them if you can find some other type of gender nonconformity. If a person is LGB, a bigoted employer will be extra-attuned to any other gender-nonconformity that they exhibit, including things that would pass unnoticed in a straight employee. This loophole won't be exploited in every case (either because employers don't think of it, because they fear courts wouldn't buy it, because many LGBs do conform in other ways, because the nonconformity in question can be classed under the giant exception for dress codes that the ENDA-with-T unfortunately still includes, or because their conception of their employee's nonconformity is too tied up in their identity as LGB so they can't separate out any other nonconformities). But it's not quite right to say that we can fully protect LGBs now and address Ts separately at a later date.