I found it odd that Smith and Webster didn't bring Whisehunt to STSP, but it was likely a scheduling issue, as the San Diego coach is a busy man these days. He has also been linked to the Detroit Head Coaching job thus far.
The ex Arizona coach got his first real run in the NFL during his time with the Steelers, where he was a TE coach, and then an offensive coordinator in the wake of Mike Mularkey's departure for the Buffalo Bills in 2004. His performance there was notable, including a now famous wide receiver reverse call to Antwan Randal El in the Superbowl.
Personally, I don't have any real interest in Whisenhunt as a Head Coach. He had plenty of time to show he was the right man for the job in Arizona, and his only real accomplishment was riding a stellar season from Kurt Warner and Larry Fitzgerald. He is no doubt an accomplished offensive mind, but his last stint suggests he was unfit to coordinate a football team as it's head.
There is no doubt he ownership in Arizona interfered often during his tenure, and I expect that had something to do with his performance in the desert, but that said, his devolution to an offensive coordinator for the Chargers has done wonders to showcase his real talent. This is likely Webster doing his due diligence while waiting for Seattle to be bounced from the playoffs. Let's hope that is sooner rather than later.