UPDATE: Unfortunately, the weather doesn't seem good, at least in Alexanderplatz it is starting to rain, and the forecast doesn't seem better! So the event will be moved for tomorrow (Sunday), at 4.00pm (it closes at 6pm), if it affects your plans, please RSPV no.
Let's start 2014 with a fun activity and go to ice skate in probably the best place to do so in Berlin: http://www.horst-dohm-eisstadion.de/
Have an awesome new year! :-)
It's 3.30€ to skate 2 hours, and varying amounts to rent ice skates, from 1 to 2 hours.