The last talk of the Summit is scheduled to end at 7:30, and the talks have been going late during the day. So I wouldn't expect anyone from the Summit to show until 8pm.
Edit: I'm scheduled to attend a speaker's dinner after the last talk, so I won't make it to the meetup until late.
Since lots of us anticipate being in New York this weekend for Singularity Summit 2009, it seems like a great time to hold a NY-area Overcoming Bias/Less Wrong meetup! Whether you're attending the summit or not, do consider dropping by the 92nd Street Marriott any time after 7PM, where you will find a lively group of rationalists discussing and dissecting the day's events, and the ideas presented by the summit speakers. We'll be meeting in the hotel's internal restaurant, which should be open until well after midnight.
RSVP at the Facebook Group or see this event in Google Calendar.