Delta has released more information about the 2015 program changes coming to SkyMiles, and flyers will have a cap as to how many miles they can earn per flight. Delta says, “With the 2015 SkyMiles program, members will earn miles toward award travel based on ticket price (base fare and carrier-imposed surcharges, but excluding government-imposed taxes and fees) for Delta-marketed flights, instead of distance flown. So when you pay a higher price, you will be rewarded with more miles.”
But the miles earned are capped at 75,000 miles per ticket and Medallion mileage bonuses will count towards that 75,000 miles.

Bottom line: As Gary Leff of View from the Wing pointed out, “Delta’s 125,000-mile-a-year Diamond members will not earn a single additional mile for business class tickets over $6,818.18 (in base fare plus fuel surcharges).”