Vanessa Lengies joins Glee as bad girl Sugar

Vanessa Lengies from American Dreams and Hawthorne is joining Glee Season 3. She'll be playing Sugar - described as a cross between Molly Shannon and a New Jersey Housewife.
I really don't understand why they keep on injecting new blood into Glee. Obviously the message from the Glouche is that he thinks the current cast is just not good enough.
Read also: Mercedes new boyfriend on the show looks like he's in his 30s.
From TV Line:
American Dreams alum Vanessa Lengies is joining the Fox hit’s Season 3 cast in the recurring role of Sugar, a new student who is described as a cross between Molly Shannon and a New Jersey Housewife.Sugar was born with a silver spoon in her mouth and a tin ear. Basically, she can’t carry a tune to save her life, but I’m guessing that won’t stop her from auditioning for a spot in New Directions.