I see Tara as a kind of F1 version of elizabeth. She was brought in as a replacement of a popular character (not sure if she was meant to be Penny's replacement who was late or Freida's replacement who was early) by the writers who have a storyline planned for her (I'm guessing) so was made a main character.
However the writers did not predict everyone would hate her, I'm guessing again but doubt she has many fans. So they will just get rid of her when her contract ends. Until then she is given small pieces of dialogue and irrates people. Then about three months before she leaves, a small side story will be given to her to explain her exit. She will be paired with a established popular character, probaly elliot or oliver, to improve her scenes so viewers are only complaining slightly. Eventually she leaves with the minimium amount of screen time possible, just enough to say "I'm off to x to do y". A few characters pretend to be sad.
The department (Darwin in this case) move past it and soon she is forgotten, with no-one keeping in contact or caring enough to bother meantioning her. I think she will probaly be gone by christmas, earlier if we are lucky.