As is my tendency, I'm speaking as the devil's advocate. What is the practical difference between Don't Ask Don't Tell and what things will be like in the military if and when it is repealed?
When I was in the Marine Corps, if DADT wasn't the law, it was certainly the practice. We all served with people we suspected were gay; and speaking for myself only, it certainly didn't matter in a personal or professional relationship with those folks. To be clear, I never spent any time in a war-time foxhole and so obviously wasn't in a position to evaluate my feelings sharing that situation with someone I knew or suspected was gay. I can tell you with all certainty it would not have mattered to me.
But that's really not what I'm getting at. How will things be any different in the military if gays won't have to conceal who they are? Do you think all of a sudden there will be openly gay (insert whatever slang here you choose -- flaming, etc) people wearing a uniform? Do you think suddenly people in uniform will be walking around limp wristed? Seriously, just because the laws change doesn't mean day-to-day life will change. There will still be those non-gay members who it doesn't matter to and will be your friend, and there will continue to be those who'll want to take you out back and beat the hell out of you.
So with that backdrop, gay people know they'll still need to live their daily military lives the same way as before. There will still be bigotry regarding promotions. There will still be a military dress code and rules of comportment.
Understand this: I believe every one should be treated equally and fairly, and I believe DADT should be repealed; but also that I served and realize that the military is a special universe, shall we say, with special requirements. If I thought for one second that repealing DADT would negatively effect the daily morale of troops or create an environment that could be dangerous to those who are fighting our wars, I would sadly be against it.
What am I missing?