A patent application from Apple indicates the company may be working on a second version of its Apple TV:
A new Apple patent may give some foresight to the company's plans for offering a "true" multimedia center experience for the living room, as either enhancements to the Apple TV or an entirely new device. The patent is for a "Multi-media center for computing systems" and describes a system involving a central multimedia hardware hub that can make use of a number of external "modules," all controlled through a centralized menu system on the device.
These external modules can consist of anything that a multimedia center might want to read from, be that a computer, iPod, external DVD player, or hard drive. However, the module could also (speculatively) be something like a recording device or something to stream from/with, like a Slingbox. According to the patent, the modules would not interact with each other at all but would be managed dynamically by the central multimedia center through a main user interface. The device will also be able to function as a traffic manager, with the ability to "instantiate and keep track of media-modules, route events associated with user input, and control what is displayed."