For you late night revelers - you will be able to get a safe ride home!:

“On New Year’s Eve (Monday, December 31) we will be operating a regular Saturday schedule with additional service during the AM and PM peaks. Plus, we will have extra afternoon and evening inbound service, and, of course, overnight service into the “wee hours” of January 1. Last trains will leave Grand Central between 5 AM-5:33 AM. See the special Holiday Timetable for details on both of these days. (We ask that you please refrain `from bringing alcohol on our trains on New Year’s Eve and early New Year’s morning.)”

Update: I actually took that last 5:33 AM train with my New Year’s buddies, and it was completely full - a somewhat agonizingly long non-express ride. All better now though. Happy New Year!

Via MTA