Just ran into this myself; realized I was out of developer and thought I would go buy some XTOL today from Adorama (near my apartment; always had it in stock) and they don't even list it anymore (I'm sure they will when they get the new version).
B&H, which is less convenient to my apartment but a possibility, is also out of stock. They do list the "old" XTOL part number as discontinued, and they show a new XTOL part number as coming soon.
Here's hoping. For now, I guess I'm going to have to start planning ahead a bit more than I'm used to.