I spoke too soon on the reservations-required scheme being dropped. There is one restaurant here in NYC (Zocolo @ Grand Central Station) that has pulled the "disappearing act" a couple of times on me. I see now they have returned on a reservation-only basis.

"Good Evening Mr. Cheapskate ... I mean Mr. Scrounger. An iDine party of one I see. Our personal favorite!"

They do tout the PDA listings feature, which I suppose is nicer than fumbling through a bunch of letter-sized printouts.