This Village Voice article has a run down of a number of great restaurants being forced to close due to the price of rent in Manhattan. Restaurants are following bookstores, which are also suffering from the cost of doing business in this part of NYC.
I suspect low margin businesses like this will move to the other parts of NYC and away from the big rent/big money sections. It will be interesting to see the migration both of the businesses and the people. Compared to the way Manhattan used to be in the later part of the 20th century, this is a better problem for them to have.
For more on the bookstores closing, see this piece in the New York Times.