Chaffetz has said he will not run for office in 2018. This is significant not just because there were thoughts he might run for Hatch's Senate seat (Hatch has said he is going to run again) but more significantly, it's much harder to re-fill an empty seat than get a congressperson reelected. This would leave the GOP very vulnerable in that opening.
Now today, word is bubbling up that he won't even finish the term. This could mean one of two things: kompromat (which is what everyone's tweeting about, and Snopes is calling unfounded thus far) or to put someone in the seat now who can then run for reelection. I'd love to believe the former (because I'm a petty dog), but I wonder if the GOP power brokers convinced him to fall on his sword and do the latter. It's going to be some interesting watching.