When I profiled the Metropolitan Life Tower (and an unusual postscript) a couple of months ago, I mentioned that Daniel Libeskind was working on an addition to the building that would dwarf the iconic clock tower. New York magazine has a rendering of what the building might look like, taken from the architect's new book.
Initial designs show a glass-curtained tube with cutaways spiraling up and around the facade to reveal segments of terraced verdure, like cultivated patches on the side of a steep alpine slope. "We didn't just fill up the tower," the architect says. "We've taken space away [from the apartments] to create the gardens," which are actually balconies tucked within the envelope. "It's as if nature has come back into the city," he says.
Update: More photos and details here.