Douglas Development has been aiming to assemble most (if not all) of Square 451 for a mixed use project.
Below is a screencap of results from the DC Real Property Assessment Database for Square 451.
Lots of Douglas Jemal entries. It’s possible Douglas Development plans to build around the 6th Street properties owned by Chumpitazi. The same may also be true for 600/606 New York Ave as that is the corner of New York and 6th. However the hold out of 628 New York Ave will likely keep this paralyzed.
Update (8/27/2008 8:00PM): Image of 628 New York Ave.