Galaxy Tab has sold over 2 million units
Well they have shipped them at least. Honestly there is not much of a difference, in a few days the customers will have bought them and it then they will have sold the units. Samsung credits their success with the fact that it is sold on 200 carriers in 94 countries!
The sales are being stifled of course by the uncertainty of Android 3.0 on the current Galaxy Tab model. Recently I saw that it has been ported to the Nook Color E-Reader. It was not very robust, but the Galaxy Tab has superior specs than the Nook. With out a doubt there will be Android 3.0 on the Galaxy Tab through unofficial channels and possibly through official ones.
In the same period of time after its launch (three months) the iPad had sold over seven million units. This is largely due to the lower price point with the Wi-Fi version of the tablet.
The Galaxy Tab is still the most popular Android powered tablet by an enormous margin.