Looks like Valve recently added a way for devs to get peoples game libraries through their web api. They recently added a global limit on the Steam Community XML/JSON feed, making the games?xml=1 feed slightly unreliable during peak hours.

However using this API call you can quickly get the appID, name, last 2 weeks played, total playtime, image icons, image logos, and community visible stats of a specific steam users game library.

An example URL would be: http://steamproxy.net/steamapi/IPlayerService/GetOwnedGames/v0001/?key=XXXXXXXXXXXXXXXXX&steamid=76561197960434622&format=json

For more info: https://developer.valvesoftware.com/wiki/Steam_Web_API#GetOwnedGames_.28v0001.29