All rumors seem to point to a "Mini iPad". So that's what I'm going to assume it is at this point. The invite says something like "We've got a little more to show you". Let me make the keyword in there that would make my guess and what everyone is thinking seem accurate. "We've got a little more to show you". All in all it's likely just meant to stir up rumors and the like. However, there have been leaks from factories reporting iPad Mini production so I'm not too sure this is just a wild rumor.