Photo courtesy of Robert at the CURBED blog.
Here's a look at the first test of the waterfall on Governors Island. As previously noted, this is in between the ferry dock and Building 110.
Robert's blog has some more new pics of the other waterfalls in testing, although the one directly under the Brooklyn Bridge has yet to come on:
http://curbed.com/archives/2008/06/19/waterfalls_are_very_turned_on_governors_island_revealed.php?o=0