Many thanks to @chintankamani for tweeting the news!
It looks like Keanu Reeves may have slipped into NYC for The Kitchen Spring Gala Benefit honoring Robert Longo that is being held tonight in NYC. He is an Honorary Chair for the event along with Michael Stipe, Janelle Reiring and Helen WIner.
The event takes place tonight, May 22, 2014 at Cipriani Wall Street. You can read about the details here.
Update: Someone who is at the Gala has posted a short clip from the taped message that Keanu has sent to the Gala so it looks like he is not in NYC for it.