Update: Northwest has added the same charge for tickets bought on or after 04/22 for travel on or after 07/01.
Delta will now charge $50 for checking a 2nd bag on all international tickets bought on or after 04/21 for travel on or after 07/01.
Last February United started charging $25 to check a 2nd bag on domestic tickets which was matched by all major carriers. Last May AA started charging $15 to check even 1 bag on domestic tickets which was also matched by all the major carriers.
I’m sure it won’t be long for the others to catch up and start charging for all checked bags even on international tickets…
As usual, Elite members and their companions are exempted from this fee.