I bet this is real... But it's not for the tablet, it's for the new iPhone. The tablet is a fake and the event is to announce new iPhone, new iPhone OS, iLife, and cloud iTunes.
My problem with the slit is that it rules out stereo. I suppose you can say it is ment to be used with the earphones for that but stylistically it doesn't seem like something Apple would do. However the latest news is that this design is close to accurate, if so a lot of people are going to have to eat their hats.
My take is that making it look like a giant iphone is just asking to be laughed at. Is this just false info, a joke on us?