With the Delta-Northwest merger, the airline is revisiting several of its fees. The big ones, an elimination of award ticket fuel surcharges and charging fees for first checked bags (elites and premium class passengers are excluded).
The elimination of fuel surcharges from US and US/Canada-departing itineraries is great (they really ought to eliminate these fees from non-North American departures), but Delta still won’t put holds on awards booked by phone (and not all awards can be booked online, and those awards booked by phone incur a fee) and charges extra for awards on partners.