Also, there is a RESTful API to query item data on battle.net:
http://blizzard.github.io/api-wow-docs/
Example for castlebreaker bracers:
http://eu.battle.net/api/wow/item/103759
(Replace eu with us for US server data)
Edit: Similarly, Wowhead has its own thing as well, adding &xml to any wowhead url will give you the data in XML, without all the page markup:
http://wowhead.com/item=103759&xml