There have been a number of problems recently at the World Trade Center site which have slowed construction of what was formerly known as the "Freedom Tower" and has brought construction on the 9/11 Museum to a halt. Also, construction for a planned WTC 3 tower that was supposed to be 80-stories tall may now stop at the 7th floor due to a lack of tenants for the building.
All this was reported by the AP today over on the HuffPost's NY page. The slowdown on World Trade Center 1, which was rising at a floor a week, is being attributed to technical difficulties as the building passes the 90-story mark. But problems with the other projects are more complex, involving a problem in the steel production for the site and political/budgetary disputes with the Port Authority.
The bottom line in all of this is that completion of the site is going to be delayed for months and possibly years, with the opening date for the 9/11 Museum being pushed to 2013 at the earliest. It's disappointing news considering how so much progress was made in the last couple years. Hopefully, the mayor can intervene and get these entities working together to complete this massive project sooner than later.