I think Shanahan is a Top 5 coach in the NFL and it may have been his duties as Head of Football Operations that dropped his coaching ability down several notches. In the past, he was saved by one Gary Kubiak who had the foresight to see how untenable the situation was becoming in Denver when he left in 2005; almost prophetically seeing the eventual demise of the Denver Broncos.
Or perhaps more likely, Gary Kubiak's departure actually caused the wheels to fly off this team which led to the eventual dismissal of Mike Shanahan. I think Kubiak may have been Shanny's butt saving assistant all those years. Being just a head coach is one of the most demanding jobs on Earth, yet being head coach as well as GM could easily be impossible. Kubiak made it possible for a decade, but when he left Shanny no longer had anyone he could really rely on. Not only that, he began to pay for past mistakes in the draft and free agency.
For what it's worth, Shanny is a top notch coach and he will be successful wherever he goes. Hopefully he will be able to just concentrate on coaching so that his naysayers will realize just how good of a coach he really is. I would even say he would make an excellent GM, if that was his only job. Trying to be both head coach and GM is too much for any man, even Mike Shanahan. The Mastermind will be back and hopefully we won't have to see much of him in the future. We all know how he handled the Raiders all these years....
As for the future, I think Pat Bowlen has his man already and moving Raheem Morris' interview up two days only reinforces that belief. I expect an announcement the day after the Morris interview - that will satisfy the Rooney Rule - and a new era can begin in Denver. You can call Bowlen many things, but once he thinks he has his man he doesn't change his mind. Many might even see this "interview" with Morris as a lip service tribute to the Rooney Rule, but really it's just Bowlen doing what is necessary to hire the guy he wants to hire. NFL owners do not have the freedom to be racist anymore, the business is too competitive for petty things such as that.