I can assure you, Kev, that DL does in fact take WN very seriously.... but for all the talk about how much damage WN has done to network carriers, it is very clear that there is a clear line between where they have had success and where they have not..... CO, DL, and NW have largely kept WN at bay in their key markets while UA and US have been fertile ground for WN's incursions. In markets that AA has wanted to keep, they have done ok but let's face it that AA has turned four hubs over to WN... RDU, BNA, SJC, and now STL.
Also, don't forget that DL has the largest average gauge of domestic aircraft in the US which makes them more than able to compete effectively against LFCs.... as evidenced by why WN is pulling back in SLC. ATL is obviously a much bigger market but there are very few markets in the US that offer as many seats as key markets from ATL. DL has more than enough capacity to throw into markets that WN chooses to enter and DL's current plans to add seats to most of their domestic aircraft types only drives down costs while adding seats that can easily be used to compete with WN.
Another data point of interest.... DL boards more than 3 times more local domestic ATL passengers than WN does at any of its other stations and more than 4X what FL currently boards. With the number of gates that WN has to work with in ATL they simply cannot come anywhere close to providing a level of service that will put them anywhere close to the size of DL. OTOH, in DEN, WN's largest operation in a network carrier hub, WN now boards 85% of the number of domestic passengers that UA boards. UA has given DEN to WN and it is no surprise that DEN is now one of UA's least profitable hubs.
Further, WN's MDW "hub" carries about 50% connecting or through passengers which means WN really only fills half of its revenue seats with local MDW passengers, an airport at which it dominates service.
WN can indeed set up an operation and they strategically need to.... just like they need to in NYC and why needed to add MSP but neither are any guarantee of success for WN in ATL. ATL may well be one of WN's largest operations in terms of airplane movements but they will be substantially smaller than DL.
Finally, DL has the lowest costs of any of the network carriers.
DL is very well positioned to compete against WN....
in contrast, I take it you notice that UA decided to add LAX-PVG right on top of AA. As for DL vs. AA, you might want to note that DL - not AA - carries more local passengers between JFK and MIA. DL has also set up "light housekeeping" in LGA-ORD, one of AA's key domestic markets...
Nicky, the Wright Amendment is only a few years from being fully repealed which means that WN will be free to fly to the entire US from the airport closest to downtown Dallas. WN is construcing a new terminal and is also planning about what short haul flights they will pull down in favor of more long haul flying.
WN is a major carrier now... but to think that any one carrier is exempt from their competition is naive... but thinking that DL will be most negatively impacted by WN is not at all in line with the history of how and where WN has found success competing against the US network carriers.