Here's a quick read on Milbank, they're current in JP Morgans building but it looks like Milbank will have to find a new home. The article indicates Milbanks potentially looking at 350,000 sf. If my limited knowledge of law firms serves me right, NY law firms are constantly looking for new space, see 250 W 55th leasing 900,000 sf of its 1M sf to law firms, so I'm surprised no ones jumped here. Even a PE firm could eat up a mere 400,000 sf.
I can't imagine there are more than a two or three vacant spaces of 500,000 sf. Hope to hear some good news soon.