I don't know if I could ever own yak but I think they are absolutely adorable. I think it's the whole big fuzzy cowesqe thing because I LOVE LOVE LOVE Scottish HIghland Cattle and their big shaggy selves too.
On a side note I was watching food network and their is a resteraunt that serves gourmet exotic and game burgers (Maybe in Boston) and besides bison, ostrich, kangaroo (yikes!), caribou, and a few other odd ones they also do Yak.