I meant to post this this morning, and only now when probably all the newstands are sold out, I've remembered.
Amanda Hesser has an excellent piece in the Dining In/Out Section regarding the $20.02 promotions which restaurants now seem to be running every two weeks.
The bottom line is that there's a lot of disparity in terms of quality of food/choice/service, etc., which I guess is what you'd expect, but it is not easy to find a high quality meal at such a deep discount anywhere without surprises (she writes, for example, of $14.00 Chardonnays with $20.00 lunches at certain places, etc.) Anyway, in my experience this promotion has usually been a rather cynical gimmick. Yes, there are a couple of high end places that live up to their reputations regardless of the price, but for the most part, if you're gonna pay rock bottom prices, don't expect top-flight experiences.