Probably wishful thinking. He hasn't coached in college or recruited in 20 years. If he does get hired, he's going to find out very quickly that the college game is dramatically different than the NFL. 2011 will be an eye-opening experience (for reference, see Mike Sherman's 2008 A&M team or Bill Callahan's 2004 Nebraska team).
Even Nick Saban went 6-6 his first year at Bama, including a loss to UL-Monroe.
And its their past glory that still keeps them in the recruiting game. Miami runs a pro style offense, and still is one of the best schools in the country, in terms of getting their players ready for the NFL. They are two years removed from the #1 recruiting class in the nation, had a solid class last year, and have some high ranking recruits for next season. Talent hasnt been an issue the past couple of seasons, coaching has. They have good relationships with most of the top high schools in the county, and a Gruden hire would be extremely beneficial for recruiting, which is just as important as coaching in CFB. And IIRC, Gruden is a pretty good coach as well.
And this is why I don't think they will try to get Mullen. He is a dedicated spread guy. And I don't put much stock in recruiting rankings. Texas has a roster full of 4 and 5 star recruits, and we see what happened this year. The same thing happened at Florida. I also would be shocked if Gruden went back into the college ranks. The transition from NFL to college isn't always successful. For every Pete Carroll, you get someone like Bill Callahan. The jury is still out on Mike Sherman.
I wonder if Tommy Tuberville would be interested in the Miami job. He has said that is his dream job, and I bet he is kicking himself for not taking it when they hired Shannon. I wonder if he would leave Texas Tech after one year to take the Miami job. I know one poster around here who would be happy if that happened.