Sams Club - Ultra dual battery charger in stock
Looks like availabily of accessories is hit or miss. On Amazon the charger is shown to ship in 1-2 months. Best Buy doesn't have a release date listed. However, the charger is available on Sam Club's site with a delivery date of just a couple days. Weird.
FYI...looks to be shipment only, not available at the brick and mortars. Although you'll pay a bit more, you don't need to be a member to purchase the charger.