I would disagree about the best place to be is on Main Street, however we do stay in DL. I don't like being in the middle of the crowds where you can't breath. I prefer the music and entertianment at Small world, over that at the castle, and you really aren't missing much. One thing I love is that over the past several years, rather than making the castle the main place to be they have different areas with different types of music. Small world is usually radio disney/NY Rockin Eve, and they do live cut throughs to NY all night. We usually tape it so we can see it at home. Last year they had some good shots of our daughter dancing with Goofy. They have stuff over at rivers of america, and in tomorrowland. Each area has it's own type of music so you can just go where you are comfortable. Fireworks are at the regular time with snow, and then again at Midnight. They make a big todo at 9, then make and hourly announcement till Midnight.
While I've been in DCA on NYE, I've never been there late, we are always at DL at midnight. They give out hats and horns. Usually starting around 7 or 8. Don't get in line to get them, just wait a while, and you can walk right up. People start lining up, but as the evening goes on, it's just walk up.