I did a google search earlier to see when the book fair was going to
be at the Armory on Lexington Avenue. I couldn't recall if it was
January or February, though I remember it being bitter cold last year.
I found this message on the organizer's website:

Books at the 25th Street Armory
69th Regiment Armory
68 Lexington Avenue New York, New York

The January 2011 Book Fair has been postponed until January 2012.

No further explanation. There were nearly 50 dealers last year, so
it's a great loss. I'm planning to go to the Greenwich Village fair
next month at PS 3, and hope to find some good things there.