The 40th anniversary is largely remembered for the civic rights protests that marked the event (and which sets the stage for the opening of Goodbye, Lenin) and the phrase Mikhail Gorbacehv is supposed to have uttered to the leaders of the GDR, "Life punishes thosewho arrive too late".
This is an extract from Time magazine about the 1989 anniversary:
The timing of Mikhail Gorbachev's visit to East Germany could not have been more awkward. On the 40th anniversary of the country's founding as a separate socialist state, the government in East Berlin found itself utterly humiliated. Like storm-besieged dikes, the borders of the country had sprung one leak after another, and thousands of refugees were pouring out. The routine anniversary visit threatened to turn into another diplomatic nightmare for the Soviet President, fraught with the kind of tensions and prodemocracy demonstrations that marred his trip to China last spring. It was Gorbachev's message of change, after all, that had largely inspired the freedom flight.