I was downtown today and happened to have my camera(!). The following two (blurry) photos show the installation of the covered pedestrian tunnels.
In the shadow of 555 (I was taking pictures of the 621 progress, but it was so dark, they turned out awful):
From N Street with Capital Plaza in the background:
An aside: what are they doing to Capital Plaza? renovation?
EDIT: Capital Square not "Plaza", oops