As reported on Wowhead, if you've completed the legendary cloak questline before patch 6.0 drops, you'll be rewarded with a new title, Legend of Pandaria. It's like most titles in that it can be used even by characters that didn't earn it (I've only earned it on one character, and that isn't him above) so if you have managed to complete the quest, it's a nice little bonus.

I'd still kind of like it if they allowed us to complete the quest once Warlords of Draenor dropped if we had already started it, but I won't say no to another title. I love those things. Nothing's ever going to beat Death's Demise, though. Still my favorite title ever.