I disagree. I've seen a bunch of hot DL FA's. I remember PHX-JFK one time on a 738...couldn't stop staring at her.
I have never flown NWA, but seen pictures and it does look pretty bad. DL is definitely getting new seat covers to replace every NWA seat cover. Every plane is getting repainted. Cross-fleeting is in progress now, and FA's don't have much info about the other airline's procedures. Soon all of the NWA employees will be adapting to the DL procedures. DL and NW gates are being moved around so they will be close together. Just wait and things will be better.