We were supposed to get the new "Berlin Brandenburg Airport Willy Brandt" (BER) by 2011, then June 2012, and now, according to latest statements, March 2013. That means BER will not be a WUDC airport after all.
Tegel (TXL) and Schönefeld (SXF), the two international airports currently in operation, will therefore stay open a little longer than planned before they get replaced by BER on SXF grounds eventually. They are both marked on our Berlin debate map.
One Berlin newspaper considers Tegel, the airport of the old West Berlin, a dump, which may not make it another year, but it's actually a nice one, comfortably close to the centre of the city. Schönefeld, the airport of the old East, is located in Brandenburg, directly at the southern border of Berlin. The merger of the two airports has been described as a last piece in the puzzle that is the German reunification.
[Update from October 2012: the BER opening is now scheduled for October 2013. The planning as a whole is on track to become a legendary scandal.]