I think someone touched on this before but it seems like the towers might not be rising for quite some time even though the project has started. That being said, I don't think anyone thought this was going to get going as quickly as it has and the brandywine article still says the project will be finished by 2010 (unlike this months gazette article below which says 2012). Hmmm
http://www.upenn.edu/gazette/1107/gaz01.html
The post office renovation and parking garage are slated for completion by 2010,
with the towers rising in 2012. By that time, Carnaroli said, new athletic fields will have been installed south of Walnut Street and the Franklin Field Pavilion will be taking shape [“New Campus Dawning,” Sept|Oct 2006].
The Walnut Street Bridge has long been considered a vital gateway between Center City and the Penn campus. Steinberg hopes that with Cira Centre South, the University will push the west side of the Schuylkill River toward a kind of urban-renewal tipping point.