I hope you all liked learning about Angela Petrelli's past in Season 3, including about her sister and Coyote Sands, because apparently we're going to be learning more about her past in Season 4.

In episode 4x03 "Acceptance", Christine Rose (Angela) says:

"I just read episode 4.03 and—oh, I get chills just thinking about it—I learned that 20 years ago or so, I made a decision that is going to come to back to bite me in my rear end. Angela tries her best, but she keeps screwing up. Oh well, she stays afloat with a sense of humor and a glass of wine."

Source: E!Online