The top rated comment on its wowhead page said that it can be used for transmogrification but I wasn't fully convinced so today I finished up the quest line to get the required reputation and bought it from Warsmith Sigfinna for 19g and a bit. I've already seen it on the auction house for 250g, but it must be one of those items that stay there for a long time since very little people know about it. However, it doesn't bind when you transmog to it, so you can just put it on the auction house after you're done or mail it to your hunter like I did. Have I mentioned that it also hides enchants?
Warsmith Sigfinna also sells a bow - with a wooden dragon head design which I quite like - and a two-handed axe (with the same blue glow) that can both be used for transmogrification.
I'm hoping it will be a match for the replica Feralheart gear since that has a lot of vivid blue, but for now, here it is with my resto set.