Floors 20 to 63 and 65 to 89 are office floors. Floor 64 is the sky lobby.
For the record, I don't think this building is "a piece of crap," at least not anymore...
I kinda think it would have been cool if SOM would have designed One WTC like they did with the 80-story China World Trade Center completed a few years ago. That's my only hang-up (orther than the obvious spire fiasco). All in all, I'm excited for this building.