The United States of Tara is officially a hit for Showtime.
With that in mind, Kristin Dos Santos of E! Online recently answered a fan's question, regarding a future show storyline. To paraphrase the spoiler:
Since Tara has been working on that mural for her sister's friend Tiffany, she's becoming good friends with her, up until the point where Tiffany forces an appearance by one of Tara's alters. This won't be a good idea, and the mural suffers the consequences.