Brace yourselves! It appears they're not done with us yet.
According to
this thread just started in the DL forum, YBM fares will yield only 100% qualifying miles in 2009 (was 150% thru 2008).
The corresponding change for NW would be to reduce YB fares to 100% EQM.
This change makes even less sense than most.
They're not even rewarding their high-fare customers. DL is becoming an equal opportunity, egalitarian screw job.