If this thing goes through, I expect NW to follow DL on the upgrades. You can't use miles to upgrade off most international fares, so it would seem domestic fares are the next logical step.

I have to disagree with the comment that codeshares reduce competition, though. Many on this board mention that they call NW for one price from Paducah to Timbuktu all on NW metal, but CO offers the same flights, NW metal but CO* designated, at a greatly reduced rate.

In small towns where NW is the only carrier, or DL, etc., competition would be enhanced because each airline would publish their own fares and one carrier may substantially undercut one of its partners.

Just my $.02!