Generally you are not allowed to do this without asking, and if you ask you'll either get no response or they'll say no. However that FAQ seems to say you can use it "for home, noncommercial and personal use only... provided, however, that you must include or maintain all copyright and other notices".
I'd still recommend you simply use original content, but if you must, at least keep a "Some content Copyright (c) 2012 Blizzard" or whatever.