The week after the iPad 2 went on sale, I kept expecting Apple to issue a press release announcing that it had sold a million iPad 2s within X number of days (Apple sold about 2 million of the first version in the first 60 days). However, the first week passed and now, more than two weeks later, Apple has yet to announce any iPad 2 sales. This leads me to believe that Apple won't be announcing any iPad 2 numbers until its next financial conference call later in April.
Of course, lack of hard numbers from Apple doesn't keep analysts from guesstimating just how many iPads were sold in total during Apple's fiscal Q2. Philip Elmer-DeWitt at the Apple 2.0 blog has put together a nice list of analyst estimates. The lowest estimate is 5 million iPads. The highest estimate is a whopping 8.8 million iPads. The average of all estimates is 6.26 million. Those numbers include the 14 days of US iPad 2 sales in Apple's Q2 and two days of international sales.
We'll have to wait until Apple's Q2 earnings call later in April to find out exact numbers, but some of the higher ones don't seem too outrageous considering the the long lines and high demand that still exist for those wanting iPad 2s.