She got the bangs during the second half of season 3 which was the worst Alias ever was, in my opinion.
I'm in the process of re-watching S3 right now and as much as people piss and moaned about this season...it really was a very good season. Granted some of the eps were not the best (I personally didn't like Blowback) but Missing Link, Conscience, Full Disclousure, and the one with Ricky Gervies were some really great eps. Why else would Jen have won the SAG award for it if her peers didn't think it was good??!
But back to the bangs....I agree, when she first got them cut, they were a mess. But once they started to get styled (and Jen got comfortable with them) they look great. Although, they did make her look older.
I saw the Extra interview last night, and Jen said it was good to get out. She also said now that Alias is winding down, she hopes to do more with charities and kids.