First, I believe I'm on record here as saying Brohm is a good hire for Purdue and will likely do well. If not, I'm doing so now. Having said that, Petrino will either a) Continue to win at Louisville and the buyout isn't meaningful as the Cards are not looking to change their coach, b) Not continue to win at Louisville and the buyout isn't meaningful because UofL wants the change, not Petrino, or c) he does something to invoke the morals clause, in which case the buyout doesn't apply. In a perverse way, the buyout may actually work against Purdue in that it may prevent Petrino from jumping ship before Brohm has a chance to build an impressive resume in WL. If UofL were in the market for a new coach in the next year or two, they likely would search for someone with a higher profile than Brohm currently has.
"While it's not automatic Brohm will get poached, Purdue's AD would be wise to have a plan in place in case Louisville comes calling."
My "thesis" is that Purdue would be wise to have a plan for dealing with Louisville coming after their football coach. Brohm grew up in Louisville, was a high school legend in Louisville, and became a Cardinal football legend playing at Louisville. Purdue made a good hire and if he excels, they should expect they are going to have a very difficult time holding off Louisville and even bigger suitors in a few years. Is it automatic he will leave for Louisville? No, it is not, but any Purdue fan who does not recognize the likelyhood here is simply living in denial.