At the WWE Night of Champions pay-per-view on September 16, current Intercontinental Champion The Miz will likely be defending his title (it is Night of Champions, after all).
As of right now, no challenger has been announced, but the most probable opponent looks to be Rey Mysterio.
For one thing, on paper, it makes the most sense.
The two fought in a great match at the SummerSlam two weeks ago, with Miz emerging triumphant after pinning Mysterio—clean—with a Skull-Crushing Finale.
One of the undisputed highlights of the undercard, the bout helped return the Intercontinental belt to relevance again, making it, once again, WWE’s most prominent secondary title (never mind the United States Championship; that became a glorified joke a long time ago).  
As a recent report from WWE.com noted, Mysterio suffered a concussion during the match, missing a couple of episodes of Raw and SmackDown as a precautionary measure.
Per spoilers, the star appeared at last night's SD tapings, his issues apparently being resolved, meaning he can compete at the upcoming pay-per-view if required to.
With Rey going after revenge—and the Intercontinental Championship—the concussion aspect helps give The Miz/Mysterio rivalry the much-needed edge it requires to be a must-see midcard feud.
If booked correctly, Rey’s title chase will truly be something fans can sink their teeth into. Heck, it’s not like WWE’s floundering midcard has anything else going on for it.
A continuation of the Mysterio/Miz feud would continue to help Miz, too. Since he began working with Rey, the former Real World star has blossomed into a terrific in-ring performer, his patchy, clunky performances now seemingly being a thing of the past.
That’s what finding the right opponent can do for you.
Mysterio is also better off in the Intercontinental title mix. While some may resent him being demoted to the upper midcard—feeling his overwhelming popularity and superior in-ring skills mean she should be in the main event scene with John Cena and CM Punk—at this stage in his career, it is probably the best place for him.
For one thing, after Rey violated WWE’s drug policy for the second time earlier this year, the company is now faced with the daunting prospect of firing him if he fails again (per the wellness program, it's three strikes and you’re out). For this reason alone, it would be unwise to trust him with another established run on top.
There’s also his multitude of injuries over the years. While he can still perform well, all the problems have clearly taken their toll and Mysterio isn’t the wrestler he once was.
At this point, Mysterio may simply be better off settling into the veteran role and aiding up-and-coming stars, rather than pushing himself to the limit in WWE’s high-pressure main event scene.
A Miz/Mysterio rematch also serves as a natural progression of the storyline. Sure, Rey may have lost clean at SummerSlam, but so what? After all, what kind of babyface stops trying just because he failed once?
Not Rey Mysterio, that’s for sure.