Shinsuke Nakamura vs Rey Mysterio (United States Championship)
Shinsuke Nakamura's reign has devalued the US Championship to an extreme low. What was once the leading mid-card belt in the WWE is now not even defended on PPVs. Although some of this blame can be shifted to co-branded PPVs, not enough is being done with the belt.
Anyway, since a US championship bout is not being advertised for TLC, and the Royal Rumble already has a time shortage, we can assume that the US Championship will not change hands.
Even if it will be defended, the matches will occur on the pre-shows. We can assume that Nakamura will retain the championship until Wrestlemania.
While Rey is currently involved in a feud with Randy Orton, it is highly doubtful that this feud will continue until Wrestlemania. As a heel vs heel match will not work, it can be assumed that Rey will battle Nakamura for the US title. If given time, they can steal the show and bring some spark back to the US title scene.
Although this match is entirely up for speculation, this can be a likely scenario if WWE continues to treat the US Championship as second-rate belt.