Oh, I didn't catch that it was Dale, I know it was Lori for most of it though.
Yea, after Lori's death Rick gets really sick in the comic book (I think an infection in his hand from not getting any anesthetic from it being chopped off, and not getting enough food or water) and is in a house with Carl. They are there for many days, where Carl almost shoots Rick, thinking that Rick turned into a zombie. Once Rick gets better, he starts hearing this phone ring. The phone calls last more than just a couple hours of time, they last for many days. It is all in Rick's head though, it is his way of coping with Lori's and the baby's death in the comic book. Of course in the Tv show, it is different. Lori is (spoilers) dead, where the baby is (spoilers) still alive.
Tyreese has been confirmed into the TV show. He will debut in Episode 8, the episode before the show goes on a mid-season break. Then they are coming back with the last 7 episodes of the season. I am not sure of the dates yet though.