A new patent application filed by Apple today describes an "Integrated Visual Notification System for an Accessory Device." In other words, an iPad case that will transmit visual notifications might be in the works.
The text of the application basically describes several possible methods of having an iPad case light up to notify the user of new messages, emails, battery warnings, game notifications, calendar events and so on. The device depicted looks the same as a Smart Cover, having a magnetic three panel front flap that both protects the screen and serves as a stand when opened and folded over. The contents of those three panels are what sets the proposed cover apart.