Warchief Tyrandor has already posted a well constructed tanking spec
HERE I've toyed with it some, can't say I can make anything better for a tanking spec based on the info that is available to us. I might tinker around to try to fit Lichborne in there some how with it's Fear Immunity and 25% Pure Avoidance(Assuming it's a very short CD and doesn't have any negative ramifications for tanking).