Currently DL Plat Medallions cannot use their certificates on NW. I was glad to see NW issuing certificates for Y, B AND M class, as M class is what Platinum Medallions can use with their certificates.

My hope is that this indicates M class will in the future become an upgradeable fare with miles, as DL allows Y/B and M for mileage upgrades on international fares. Since NW moved this season to provide 150% EQM for M class and 150% banked miles bonus for Y/B/M fares (which is what DL has done in the Sky Miles program for years), I suspect the programs are moving into alignment.

When the Worldperks program merges into DL's, I'll be curious to see what happens with the KLM alliance. Will the program remain the same and everyone will be able to use miles to upgrade on KLM flights or will that relationship with KLM end or possibly expand to AF?