We've heard these were coming, and now they're here: heirloom chest pieces. We just grabbed these screenshots hot off the patch 3.2 PTR. These are the level 80 versions, of course, but you can get a feel for what each chest has, statwise. You'll notice that the promised 10% experience gain is there on all the pieces, and that they are slightly bugged right now in that each of them has no armor.
You'll also notice that the names and graphics, which hearken back to old original WoW gear, mostly match up with existing heirloom shoulders, so you'll even be able to get your newbie all color coordinated and whatnot. Of course, a set bonus would have been nice too, but I'm sure we'll all be able to comfort ourselves with that nice big experience gain boost. The chests currently cost 40 Heroism badges and a bit of gold to buy, although that may change before the patch goes live.