I believe that IS where it began. SE sat Bo down and gave him more money to recruit and pay his assistants and then demanded progress, when Bo couldn't get us past 9-3, he got canned. He also probably knew it was coming.
I also agree that the longer we wait, the bigger the announcement must be. However, I'm of the opinion that SE had his man before firing Pelini, which also leads me to believe that this person was also on SE's radar since last November. In turn this leads me to believe that this person may not have had a job over this past year... A la Jim Tressel.