For the record, getting in to MK last night was absolutely doable.
Got to the park around 5 and even managed to get into Be Our Guest as a walk up with a 15 minute wait. Didn't do any major attractions, but as the night went on, the park slowly cleared out, though the mountains (save for Splash, which was pretty much walk on all night due to the cold) kept their 2 plus hour waits. Managed to walk on to Pirates, Jungle Cruise, CoP, and People Mover after 9:00.
Sat down on the curb on Main Street right after the 10:30 MSEP passed by (around 11) and stayed for the big fireworks. Walked right out to a monorail afterwards (we hustled but didn't run) and had no wait.
Not nearly as horrendous as I had anticipated, but again, I went in not wanting to do anything but see the fireworks. People with an agenda that included major attractions were likely disappointed.