Fenix makes a couple of CR123/18650 powered lanterns (CL25R, CL30R). Multimode, regulated, rechargeable, and weather resistant(IPX6). If I was looking for a one-and-done utility lantern, I'd give those a serious look.
Concur. I upgraded my 3-D Maglite to an LED bulb; the batteries have not died and are replaced as they time out. I really need a good set of rechargeable D batteries.
Energizer makes rechargeable D-cells, but they're only rated to 2500 mAh vs. 12,000 mAh for Alkaline. I strongly suspect that they are smaller NiMH cells in a D cell housing.
In your shoes, I would get Enloop AA NiMH. I know that Sanyo has their own D cell adaptors. If you're desperate, there are adaptors that can cram multiple, parallel, AA batteries into a D-sized shell. Caveat Emptor on those as I don't like parallel batteries without a pair of diodes to handle voltage mismatches.