There’s just another big gap in the north-south connection: after work was completed and U6 is back in operation, now the S-Bahn is disrupted between Nordbahnhof and Anhalter Bahnhof.
The construction work on the north-south connection will be split in two mayor phases: first from November 22nd until December 9th – and then again in 2014 the connection will be closed.
Here’s further information about the first construction phase – in german only:
www.s-bahn-berlin.de/aktuell/2013/199_norsued-sperrung.htm
But on the above information page there’s also a link to a map showing how to get around the S-Bahn-gap. Direct link to the PDF over here:
www.s-bahn-berlin.de/aktuell/2013/pdf/nordsued-sperrung_131122.pdf