The legacy airlines flying on lucrative — but highly competitive — routes between New York-Los Angeles and New York-San Francisco are all rolling out upgrades to their in-flight seating and services this year, especially for premium travelers. And now the upstart carrier JetBlue might be preparing to take the competition up a notch with a new kind of premium seating option.

A new small airline in California launched its inaugural flight last week with a unique business model: Customers pay a flat monthly fee to fly as much as they want — as long as they only fly in the carrier’s limited service area, and the flights they want aren’t booked up.

United Airlines has a new “subscription” option for travelers who have not achieved the elite status that would exempt them from fees for checked baggage and would guarantee them a spot in the airline’s extra-legroom Economy Plus seating.  United’s new plan offers one-year subscriptions to these services for set fees.

Ever since it inherited a Memphis hub from Northwest Airlines in 2008, Delta has been slowly downsizing its operations there, and now it plans to de-hub the airport this fall with yet another big service cutback.

In news of U.S. airlines, Delta raises the fees for second checked bags on some international routes; it looks like American will stay with Citigroup for its AAdvantage credit card in its pending merger with US Airways; an Alaska Airlines upgrade lets boarding passes go into Apple’s Passbook; and American plans a new transatlantic route from its Miami hub.

When American Airlines and US Airways announced their intention to merge, it was widely predicted that to win approval from the government’s antitrust regulators, the airlines might have to give up some slots at certain airports — particularly the airport used by Congress, Washington Reagan National. But now a large number of congressmen are trying to make sure that doesn’t happen.

In U.S. airline news, United Airlines quietly raises change fees for international trips, and finishes cabin overhauls on New York flights; four congressmen introduce a bill that would guarantee families the right to sit together on commercial flights; Citigroup wants to know if it will still be the provider for American’s AAdvantage credit cards; and the Supreme Court will hear a case involving a frequent flyer’s rights. 

Would you believe that a majority of airline passengers would be more willing to accept a seat next to a crying baby than a seat next to one particular kind of person? Or that one in-flight amenity is more important to them than free TV or movies? A new passenger survey by Harris Interactive turned up some interesting results.

In news of U.S. airlines, Consumer Reports readers rate their favorite — and least favorite — carriers; a major regional airline places a big order for new, larger planes; United starts a loyalty program for small business customers and adds a perk to its MIleagePlus Card; and Virgin America teams up with a new rental car operator.

In news of U.S. airlines, JetBlue has finally entered into a bilateral code-sharing relationship with a foreign partner; United says more of its aircraft now have live TV capability for passengers; airlines predict big passenger loads this summer; and Delta’s mobile app survives a legal challenge.