If Electonista's source is correct, then Apple may have find its unexpected rival in the form of an e-reader. According to the suppliers of Barnes & Noble, the book seller may have sold 3 millions Nook Color since it launched in the fall. To put the number in perspective, Apple sold about 15 millions iPad worldwide since its launch, with 7.5 millions sold in the fall. On the other hand, the Nook Color is only available in the US. No matter how you look at it, 3 millions of Nook Color in the US alone versus 7.5 millions of iPad worldwide is a sales number that Barnes & Noble should be very proud of.
Of course, one might argue that the Nook Color isn't even a tablet, but as demonstrated by numerous people, including myself, it can become a very capable tablet with very little effort:
Nook Color may have hit 3m units, 50% of tablets in US | Electronista: "- Sent using Google Toolbar"