My guess is yes, the lagoon will probably be drained and under major construction during the summer. I can guarantee that the area where the new amphitheatre is going will be walled up as they try and open the show by Spring 2010 (?), I'm pretty sure.
However, the Games of the Boardwalk and Mickey's Fun Wheel are supposed to open this April and the reopened wheel will allow for some interesting views of the lagoon under construction.