I wanted to put this in a WrestleMania discussion, but I couldn't find one, so I have a separate topic; sorry if it doesn't seem worth it.
So, with a few guys said to be walking out and many guys heading towards retirement, WWE need to start building stars more than ever. The US Title is just a prop and doesn't mean anything and the IC Title is barely relevant, so unification seems like a good idea to me.
So, here's my idea...
Mark Henry gets a shot at the US Title. The Shield has a miscommunication and Ambrose ends up losing the US Title to Mark Henry. This creates more interest in the US Title having a main eventer such as Henry holding it and he's not doing anything at the moment anyway. Also, it creates more tension within The Shield.
Mark Henry can defend at Elimination Chamber against someone, such as Ryback. A tough match but Henry comes out on top. Big E can defend the IC Title against Fandango or something; Big E retains.
Mark Henry and Big E set up a unification match at WrestleMania. You can either make it a student vs teacher program, turn Henry heel again, or have it as a game of one-up-manship, such as Ryback and Henry at WM last year and have Henry and Big E both doing crazy feats of strength and trying to one up each other.
Anyway, Big E beats Henry at WrestleMania in a quick but REALLY physical match. I mean, Big E getting Henry up for the Big Ending would be a great WM moment. Henry passes the torch to Big E (maybe Henry retires?), plus we get one main midcard title held by a new star.