Apple has filed a patent for its own smart touchscreen technology for a whole range of devices, including a tablet computer. This may indicate that the company is working on a Tablet PC but don't be too assured about it, a patent isn't an indication that a company will really launch a product.
Apple's "Gestures for touch sensitive input devices" patent claim describes a touchscreen for "desktops, laptops, tablets [...] a handheld computer [and] may also correspond to a computing device, such as a cell phone, PDA, dedicated media player and consumer electronic device." The key feature of Apple's idea is a "multipoint"-capable touchscreen: Instead of entering data sequentially, Apple thinks about simultaneous input of data: "The method also includes identifying at least one multipoint gesture based on the data from the touch sensitive device," the abstract reads. Multipoint data entry can mean "multiple fingers, fingers and palms, a finger and a stylus, multiple styli and/or any combination thereof."