The current Apple TV device turns two years old in March, and throughout those years, speculation about the development of a more robust Apple TV has been ongoing. The latest educated guesses predict a new Apple TV with Time Warner support by April, as detailed by my colleague Jim Karpen on February 13. Presumably, that box will replace your existing cable DVR box while making it easier to access content from iTunes and other Internet channels like Netflix. If anyone can make the cable guide more appealing, it's Apple. It would be ironic if the next iteration of Apple TV were to actually embrace cable and be sold or rented directly from your cable company, when so many people look to devices like the Apple TV or Roku to "cut the cord" and eliminate their cable bill altogether.
However, with the Comcast acquisition of Time Warner Cable, nothing is certain. So if you find the existing Apple TV fine for your needs, the official Apple Store has the refurbished model for just $75 instead of $99, which is a great deal. Over the years, I have bought two Apple TVs myself, one new and one refurbished, and the difference is minimal. The refurbished model comes in brown packaging instead of the fancy Apple white box, but it has a new warranty; and since there are zero moving parts and the box just sits on your TV stand, there's really little need for a factory fresh model.
Even though a new Apple TV might be on the horizon, I just bought another one. While I have two Time Warner cable boxes already, which I will likely upgrade to the next Apple TV box, there are other TVs in the house that could benefit from AirPlay mirroring and Netflix viewing, and the $75 price makes it an easy decision.