I think this is a great idea and it will make the sport more watchable.
From Associated Press:
"... The opening meet of the World Cup in Dubai on Tuesday will feature 4x50-meter mixed relays for the first time. Teams will be made up of two men and two women, and it is up to them to decide the order — so, for instance, a woman could race against a man on the anchor leg.
The initiative will be part of all eight World Cup meets. Swimming's governing body, FINA, has said the relays could be introduced at the short-course world championships in Istanbul in December and one day become an Olympic event. ..."