Of course, there's a twist. The new heirlooms like the War-Torn Ancient Bone Bow may superficially look like the old Charmed Ancient Bone Bow, but it's actually a different item. That's perfect in one sense, since the War-Torn Ancient Bone Bow now goes all the way to level 85. But it's a bummer for people who like to collect and save their points, since it means you'll probably have to rebuy it. The Vengeful Heartseeker, Battle-Forged Truesilver Champion, and many others enjoy this treatment in patch 5.2.
Granted, this is pretty early in to the PTR cycle. It's entirely possible that Blizzard intends to provide an upgrade path. But you have to spend all those points on something, and heirlooms items have always served as a very effective point sink. I suspect we'll all be buying new heirlooms soon enough.