Articles from the New York Sun indicate that there’s serious interest in auctioning landing slots at the New York area airports. Mayor Bloomberg and the Bush Administration are in favor, Port Authority less enthused. No mention of what they’d be worth, but a US DOT official said
[T]he whole point of the auctions was to generate the proceeds necessary to build out an upgraded infrastructure at participating airports.
which implies that they’re not expecting to even cover the full cost of existing infrastructure, let alone the rent (that is, what the site and the right to operate an airport would be worth if the airport didn’t exist). The earlier article notes that it would incentivize carriers to operate larger aircraft, presumably providing more capacity.