FWIW, I ordered a white/white MR on Thursday, March 14. When I took my test drive a few days before, the salesperson said she couldn't find any white/white MR cars locally in inventory. (This was out of the Dedham, MA Tesla store; but she checked a series of regional databases as far west as Chicago.) I guess that's a popular color combination, at least relative to Tesla's production.
All the news recently has been about Tesla deliveries going to China and Europe, while shipments to North American delivery centers are down. Presumably they'll ramp up to do a bunch more production for North America soon. If nothing else, they'll want to get cars out before the end of June, when the Federal tax incentive drops again. Personally, I have no problem with waiting that long. If I did, I'd look into a compromise on the car's interior and/or exterior colors.