Now I can post this without spoiler tags.... The Entertainment Weekly article said that Shane gets killed in the books very early on, but Frank Darabont thought that it was too interesting a storyline to NOT explore further. I'm sure they'll really get into the Shane/Rick/Lori triangle next season.
That "attack" scene with Shane and Lori was really hard to watch. He's starting to go off the reservation a bit, although I guess that's to be expected. Plus, you can see now why he thought Rick was dead. I'm surprised that he survived after seeing those scenes in the hospital. Apparently, all you need to fend off zombies is a hospital gurney!
The article also talks about a character in the books called the Governor, who is this evil, sadistic guy. When someone asked Darabont if Merle would reappear in season 2 as the Governor, he seemed to think that was an interesting idea. He didn't confirm either way, but he may have been covering. I think it would be a great way to bring Merle back in.