Under Peterson the Washington Huskies returned to national prominence, but in spite of recruiting some of the best talent in college football, they went 7-5 this season.
Peterson said that he needs to "recharge" and will remain with the program in an advisory role. When asked if he's going to take the future USC head coach position, he said "I'm a Husky for life". That's not a solid denial.
Peterson's resignation was considered a surprise. The Huskies immediately named their defensive coordinator as their head coach. He is considered to be one of the top assistants in the NCAA.
His resignation wasn't a surprise to me. Going 7-5 when you had the talent he had and the expectations of contending for a national title helped him make this decision. I think he's a great coach for a program like Boise State which plays in a lesser conference. I believe he was in a little over his head in the PAC 12.
Peterson's salary was rather impressive. Contrary to popular belief, the school / taxpayers did not provide that salary. The boosters, the Tyee Club, provided the money. I suspect that he was hearing rumblings of dissatisfaction from them. Once that starts to happen, you're on thin ice.