Demand for firearms is already starting to slow significantly from the panic levels of a few weeks ago. I predict demand for ammo will slow soon as well, and when the suppliers finally start to catch up you'll start to see a lot more 9mm in stores.
I don't recommend buying a gun in a caliber you don't want just because of a temporary shortage. 9mm is the most popular self-defense caliber, so once the market stabilizes it will become plentiful once again.
0331: "Accuracy by volume."