The iPhone is one of the biggest competitors to the line of RIM Blackberry smartphones. It would make sense that RIM might want to battle Apple in the new tablet market against the iPad.
Rumors have a new tablet coming from RIM in 2011 dubbed the Blackpad. The tablet is said to run the full Blackberry OS from the smartphones.
The OS would offer all the features that users of the Blackberry phones have come to know. I would bet the Blackpad if it turns out to be true would have physical keyboard, Blackberry is known for its keyboards.