You can never be sure in football, but the impression I have of Darren is, amongst other attributes he has, he is grounded, level headed and loyal (rare in football).
Based on those, I think he will want to see the job out at Doncaster and achieve the best he can with them.
He is till on his apprenticeship and I would love to see him as Head Coach to an established Premier League club one day, joining Sheffield Wednesday might derail that for him.
Whatever you decide, all the very best "Big Dave"