Peter Luger--no weekend walk-ins?
I'd be inclined to take them at their word.
But you can always take a chance, especially in this economic climate. And if they cannot or will not seat you, Dressler is across the street, and Marlow and Sons is down Broadway just past Berry. And a slew of Williamsburg restaurants are within a mile or so. You can run a Google Map on Peter Luger and then search for nearby restaurants to get a list and a map.
If you do decide to go, it would be great if you'd post to tell us what happened.
Best of luck...