the airport extreme does support WPS. it's just not very reliable with other manufactures implemations and not recognized as a true wps device by the wifi alliance.
in airport utility "first connect" is wifi protected setup push button, and pin is pin.
i have tried connecting other clients wifi devices that use wifi protected setup with my airport extreme base stations and my time capsule, and it has been hit and miss, some devices like my HTC FLYER will not negioate a connection on pin based connections, but will connect on the "first connect" setting. my hp brand printer doesn't seem to want to connect with push button, but it does connect with the pin number.
also to be officially declared a WPS device by the wif-fi alliance, the router needs to be configured automatically by a computer, say windows 7, without having to download any software, the airport extreme and time capsules clearly do not support this feature, so they will never be cerified to be wps.
as far as the reaver attack goes. i have no idea.