originally meant: happy, excited, merry, exuberant, etc.
Now it is:
1) referring to members of the homosexual community
2) used to refer to something that is annoying, stupid, unfortunate, or altogether unwanted.
-Use number two has led to a political correctness backlash against this use, I see nothing wrong with this use it is just a word, and people have their first amendment right to use it, but political correctness activists do not see it that way.
-Another issue that has arisen out of use #2 is the accusations that the people that use the word gay, are closet homosexuals, trying to distance themselves by making themselves seem more masculine. I do not agree with this; once again this is just a word, a slang term like cool or hella.
example (orig use): The birds songs in spring are gay, and lively.
1) He is a hair stylist, lives in San Francisco, and loves Broadway musicals, he's gay.
2) We have a pop quiz today? That is so gay!