Some people were somewhat upset when Caesro lost the US Title to an almost irrelevant (at this point) mid carder like Kofi after such a long US Title reign. But speculation is that Kofi is just a transitional champion, a baby face given the title just so he can drop it to another heel that the WWE prefers as champ over Caesro at the moment. It seems to me it could be one of three people, all whom I think are plausible:
Big E Langston - A couple of weeks ago, didn't Ziggler defeat Kofi and then have that followed up by Langston dropping him with The Big Ending? With Ziggler as WHC and AJ the #1 contender for the Diva's Title, I saw this as a possible setup for Langston winning the US Title soon, so that all three could have titles. This seemed to go nowhere but they could always go back to it. Just have Big E win a #1 contender's match (maybe a battle royal) and you're set.
Roman Reigns - An obvious choice, considering The Shield are starting to go after gold for the first time with the tag team titles. Ambrose and Rollins are reported as being the chosen ones to defeat Team Hell No, so perhaps Reigns is the chosen one to crush Kofi for the US Title, since Kofi is now getting involved with The Shield.
Jack Swagger - The racist All-American who hates (along with his racist uncle Zeb) anything non-America or foreign to his and their home country. Perhaps after failing to win the WHC, Kofi is out there after a title defense for the US Title giving a promo, and is interrupted by Zeb Coulter. Zeb says the only thing worse than not capturing the WHC is seeing a guy from a whole different continent walking around proud to call himself the UNITED STATES Champion. Feud begins, with Swagger taking the title and then Zeb cutting a promo about how this is now the most important title to the WWE now because of it's namesake and that Swagger and he will fight to the death (figuratively) to defend any foreigners or Americans with twisted morale trying to win the championship from them and taint its prestige.
All three are interesting scenarios - Langston being a champ along with Ziggler and AJ, Reigns being a champ along with Ambrose and Rollins, or Swagger being a champ to show everyone what a true United States Champion should be. Who do you think would be best? Or perhaps someone has another contender for winning the title, in which case feel free to spell it out.