No. Most UK citizens will not need to exchange their current digital passport for a biometric passport to travel to the United States.
Full details:
24-hour Passport Adviceline: 0300 222 0000 (see terms and conditions). Calls made to 0300 numbers from landlines and mobile phones are charged to customers at their network provider's national rate. Live operators are available to assist with your enquiry 24 hours a day.