NBC slots Wallace in 'Today' exec role.

NBC News had one surprise left in the shuffle at the top of "Today."

Don Nash, a more than 20-year vet of the ayemcast, was tapped Wednesday to take the day-to-day reins of the four-hour broadcast as exec producer. NBC News senior veep Alexandra Wallace was officially named executive in charge of "Today," a new role for the Peacock. Wallace's appointment had been expected, but NBC News brass kept the decision on the exec producer post close to the vest.

Nash, who reports to Wallace, will succeed Jim Bell as of Dec. 1. Bell was shifted Tuesday to NBC's Olympics unit, serving as exec producer of all coverage.

The changes come a few months after "Today" …