I'm hearing he wants to return at some point as it presents a challenge for him, and he said the lay-off won't matter. He coached for 27 years, and with his current job he's well aware of the current NFL and its workings.
Every year this is talked about, but I have a feeling either this year or next Bill will make a move back to coaching.

He'll make a ton of money for one, and I think he's getting bored with his current position, so its logical he gets back to coaching. There's been speculation on what team he would coach for sometime now, its anyones guess but I would think the team he does coach must have a good QB to start with. He's going to want more control over matters, and he will command anywhere from 8 to 10 million a year.

I've been hearing San Diego and it makes sense. They have a good QB in Rivers to start with, and their defense isn't too bad, they need some more weapons for Rivers and some help in their offensive line. I think Bill could make a difference for that team and finally get them back to a playoff team.
There is an opening @ SD and I haven't heard any replacement news for Norv Turnner, so who knows this might be the year.