Everyone acknowledges that gays have served and are serving today in the Armed Services. The fact that they have had to keep their sexual preferences to themselves made the difference - i.e. two gay male soldiers serving in close proximity with each other - who might even find themselves attracted to each other - would likely not even know that the other is gay, so nothing would happen between them.
But now they will know that the other guy is on the "team", so to speak. And then things would change. The idea that a new change in rules will not lead to a change in behavior is one of the reasons liberals are always shocked by unintended consequences, from welfare to tax hikes.
Where the rubber will meet the road is when the armed services are forced to deal with gay servicemen and women in the same unit and/or command chain entering into relationships with each other. This is not just a gay thing - notwithstanding rules against sexual relationships, females are quartered separately from males precisely to prevent this from happening. This is not going to be possible where homosexuals are concerned.
I'm very curious to see the policies the different armed services are going to come up with to deal with the issues that are going to come up. i.e. If (male) SGT A and (male) CPL B serving in the same unit are discovered to be an "item", how should that be dealt with? Should it just be allowed? Should they be separated - SGT A or CPL B moved to another unit - with all the chaos that would entail? Punished? Discharged?
Here's a prediction; there's going to be a jump in the number of disciplinary actions with regard to improper social relationships between grades i.e. "fraternization", and gay servicemen and women are going to be in the dock in numbers far exceeding their proportions in the armed services.
Two possible outcomes;
Mindful of the politics, someone in the Pentagon (civilian or military) is going to advocate turning a blind eye to it. At which point, cases of heterosexual fraternization are going to go up - I simply don't see how CPT Alan and SGT Alice are going to stand for being drummed out of the Army for being a couple when CPT Matt and SGT Mike are walking around holding hands on base.
The other outcome is that the military come down hard and politics would again come into play. The New York Times would eventually notice that 70% of the fraternization cases brought to court-martial involve gay servicemen and women. This would be taken as prima facie evidence of homophobia and discrimination and it would be all over the news.
Liberals are going to react the way they have always have - demand a change in the rules. e.g. African American kids failing math tests? The Conservative would say get better teachers and spend more class time on math. The liberal would call the test racist and demand that it be eliminated because it "discriminates" against African American kids.
Likewise, gay activists are going to launch a new campaign to force the military to drastically soften or eliminate the rules and regulations against fraternization because it "discriminates" against homosexual sailors, soldiers, Marines and airmen.