"Archaeologists can't wait for the tunneling to begin at the Damrak, which was once the harbor where the Amstel River met the Ij, leading out to the North Sea. In the 1600s, countless ships returning from the East Indies docked there, making Amsterdam _ the dam on the Amstel _ one of the world's wealthiest cities."
Washington Post article
Here's a link to a pretty awesome English language film about the construction.
If you go to Centraal Station, they have a display on some of the stuff they've already found. Bottles of booze, lots of knives (guess Amsterdam was once a place with lots of sailor brawling), an old pewter brooch from someone who was a member of a riflemen's guild _ sorry, that's 'ye olde riflemen's guilde' _ of St. Joris and the Dragon, dated to 1450. Who knew they even had rifles in the 15th century?
They also have some more recent stuff on display, including some German dude's Diner's Club card, dated to Feb., 1973.
So if Mr. Harald Schtuperr of Hamburg, Germany is still looking for that card _ it's on display at Amsterdam CS.