Munster estimates Apple sold 400,000 to 500,000 iPad 2s, which would mean the device has fared better than the original iPad, 300,000 of which were sold in its opening weekend.

This is only a preliminary report, but still, it’s scary. We should have official numbers by Apple pretty soon, but the Apple Online Store is reporting shipping estimates of 3-4 weeks, which seems to confirm that Apple has, in fact, ran out of iPad 2’s on its opening weekend.

Not a great day to be Motorola, I guess.