Great news about US Air. Competition is always welcome.
As for the new airline ("Bel Air") -- the fact that this company does not want to identify its shareholders would make me very reluctant to buy a ticket.
Without public bona fides, I would be concerned about safety history. Have the principals operated an airline before? Did they have safety problems? Were they forced out of business? If there is any industry that needs to operate in the sunshine, it is the airline industry.
There is also the risk to consumers that the airline may go under before your trip (or worse, in the middle of it...) but that can be alleviated by using a credit card and purchasing travel insurance.
I would be more concerned about the safety track record. This new company may be 100% OK...but by refusing to divulge their bona fides, they give the appearance of having something to hide and that makes me nervous, since I don't know what that something is...