Here is my reasoning:
- This fits the rumours of a tablet like device.
- The Kindle is Amazon's top selling product, so there is clearly a market for eReaders. This is a new device that is on a rapid upward trend.
- Most eReaders on the market today are either rather ugly or feel like a first generation product. So there is a gap in the market for an eReader with an Apple quality feel to it.
- Digital distribution of eBooks isn't far from Apple's core competency with the iTunes store. They could just bolt it on like they did with TV, Movies and iPhone applications.
This doesn't fit a lot of the rumours because a lot of the supposed leaks talk of an iSlate that is just a large iPhone type interface.