I think we can call this a definite whoopsie on the part of AMC's advertising department. If you don't want to read major spoilers for The Walking Dead (both the series and the comics) then I suggest that you turn back now. To give you ample opportunity to do so, I shall insert an large photo of Norman Reedus into this story. For practical purposes.
The Hollywood Reporter have spotted an extreme spoiler in an AMC advert for the limited-edition Blu-ray of The Walking Dead, which includes this line:
…bonus features such as: the making of the barn, an extended zombie gut scene, Shane's last episode…
Speculations have been circling for a while now that Jon Bernthal's character would not survive the second season. It began as a rumour that one of the cast members had requested to be released from their contract after Frank Darabont's departure, and shortly after this it was announced that Jon Bernthal had been cast in a lead role for Darabont's new show L.A. Noir.
Regular viewers of The Walking Dead will have noticed that Shane is in something of a downward spiral: he attacked Lori in the CDC at the end of the first season, then midway through the second season shot Otis in the leg and left him behind for the zombies in order to ensure his own escape. Finally, he decided to shave his head, and we all know that shaving your head is a sure sign of evil. It seems likely that his exit from the series will come about as the result of a breakdown similar to the one we saw in the comics.
Of course, it's not a surety that Shane will actually die, since the description merely states that it will be his "last episode". Perhaps Shane decides to take a long holiday to Majorca where he settles down and starts a lobster farm. It could happen.