Apple crossed the 2 million sales threshold this week, and looks like quite a success story.  Estimates show that if sales continue, Apple might sell 6.2 million iPads in 2010, although many of the international companies have limited stock at this time.

Gene Munster with Piper Jaffray crunched the numbers and the result was an additional 4.3 million items sold this year. With 2 million are already sold this would translate to 6.3 million devices sold in 2010. These numbers show a really strong sales and mean another 25 cents GAAP earnings per estimate.

However, when going through the supplies part, Munster said that sales can be limited by availability. This is because of the low supplies. He mentioned that during this weekend the international sellers boosted sales with another 100,000 units.

The problem might begin when the stores run out of iPads. “We conducted 25 checks at Apple stores in the U.K., Germany, France, Japan and Australia and found that supply does exist after the first weekend of sales, but availability is very limited” – said Gene Munster.

His research shows the following numbers: there were 14 international sales contacted on the launch day – last Friday – and they all had about a third part of their stock sold. The following working day brought other updates: 36 percent were entirely sold out. Munster checked the stores in the United States, too, where he found that 74 percent of the units were completely sold out.

As a conclusion, Gene Munster stated: ‘in other words, supply at international stores is limited and declining, similar to trends we saw at U.S. Apple stores.’