Great news!!!

On May 6th Delta and Northwest will begin phase 1 of its reciprocal pass travel benefits. To travel on the other, you must get a paper ticket, just as you do with ZED fares, however, the fare is $000.00. Of course, just like zed, you'll be the last on, and you must dress to the nicer of the dress codes.

This looks pretty fantastic. I ended up not needing it, but I almost purchased ZED the other day on NW. Would have been pretty pricey, too.