The three significant announcements and one non announcement from Southwest Airlines in recent weeks:

• Southwest yesterday announced a major addition to its route network: Newark. Flights should begin March, and the airline expects to be operating 18 flights a day by June 2011.

•The airline also ordered 25 more 737s last month. At the time they claimed that the extra planes would be used simply to replace older aircraft on a one-for-basis. That could still easily turn out to be correct, but it’s also the first step towards growing the fleet.

• Southwest is looking at bigger planes. It currently flies mainly 137-seat Boeing 737-300 and -700s but now is interested in possibly taking some of the larger -800 as well, which would seat about 175 in their typical seat density. Southwest’s flights are fuller then they’ve ever been before, which explains their sudden interest in the -800.

• No word yet on exactly when Southwest will begin flights to Greenville-Spartenburg or Charleston.

So how does at this impact if/when Southwest comes to the CLT? Good question. For the past two years, Southwest hasn’t grown their fleet but rather has shifted capacity from weaker routes to add new destinations. This has resulted in their planes being fuller than ever. If the economy improves at all, Southwest will have some significant internal growth possibilities with not all that many additional aircraft coming in. Southwest now may have just cautiously begun adding capacity, which should improve Charlotte’s chances of attracting the airline eventually — all other things being equal. Still no reason to think it’s imminent. The low hanging fruit is probably Cincinnati or, if they’re so inclined, any number of Charleston-sized markets.

Bonus non-Southwest updates and things:

• US Airways adds flights and destinations from LaGuardia. More proof the Delta/US Airways slot swap is dead but this also highlights the role that LaGuardia can play in US Airways’ network as a regional hub. And the more that LaGuardia handles, the less likely it is that flights to secondary northeast destinations might come to CLT in the future. The airline also noted that its LaGuardia operations were marginally profitable in the second quarter.

• Albuquerque wants more air service. It doesn’t have nonstop flights to Charlotte, US Airways’ largest hub. Albuquerque’s list of targeted destinations they’d like to add includes Burbank and San Jose, CA, Detroit, and Boston but not Charlotte. OK.