We'll be there . We were there last year for New Year's Eve too.
I don't know if it closed, sorry. It was *very* crowded, of course. But we were still able to have a good time. Just get to the shows early (even 20 minutes should be enough for most of the shows, assuming you don't mind a bad seat). The really popular shows (Sesame Street, the Christmas pageant one) you need to get there really early.
The food lines were crazy long, even at off peak times.
We left around 8 or so (we have a toddler), so I don't know how crazy it got closer to midnight.