CLT-JFK will be a hard fight for B6. US has a heavy schedule to both LGA and EWR - both more convenient - and a firecly loyal following - many of who have deep pockets. With HP backing it, US can afford a fare war and few except for some leisure travelers who want the novelty of B6 will have the incentive.

Note the AirTran and Independence, they make a very very small percentage of flights at CLT right now. And indpendence looks to be going under.