Question: I would like to know if there are tools available to identify what WPS method is actually enabled on an AP?   

I would like to know also if there is a way by looking at packets to know which WPS method is enabled?

Answer: 
You can use the latest aircrack-ng suite (Aircrack-ng 1.2 RC 2) to check for WPS enabled access points. I'm assuming your wireless interface is called wlan1:

* airmon-ng start wlan1
* airodump-ng wlan1mon --wps

You can read more about it [here](http://www.wirelesshack.org/aircrack-ng-v1-2-rc2-adds-new-options-wlan0mon-with-wps-support.html) for example. You could use the [wash](https://code.google.com/p/reaver-wps/source/browse/trunk/docs/README.WASH?r=87) tool as an alternative, but I'm not sure whether it is still being updated.
Nothing better than to directly have a look to the WPS tag in the AP PROBES.
Wash or airodmp-ng do that for you (but information is less complete): `sudo iw wlanX scan`

check this as an example output: 

```
WPS:     * Version: 1.0
     * Wi-Fi Protected Setup State: 2 (Configured)
     * Response Type: 3 (AP)
     * UUID: ebd86104-5cb3-4a92-b43c-6547abcb2dc2
     * Manufacturer: Celeno Communication, Inc.
     * Model: Celeno Wireless AP 2.4G
     * Model Number: CL1800
     * Serial Number: 12345678
     * Primary Device Type: 6-0050f204-1
     * Device name: CelenoAP2.4G
     * Config methods: Label, Display, Keypad
     * RF Bands: 0x1
     * Unknown TLV (0x1049, 6 bytes): 00 37 2a 00 01 20

```

This is what you can see in the probes