Don't forget the BUST factor. Coming out early increases it. However, the bottom line is Harbaugh. He leaves, and Luck leaves. Luck is probably including Harbaugh when he says, "Family."
Meh - we're going to lose sleep over whether anyone we pick at one overall will be a bust. Seems like a smaller chance with Luck regardless.
I am inclined to agree that he won't stay if Harbaugh leaves...but I thought we all basically took that as a given.