He's already been the US Champion and it wasn't a memorable reign for him because he barely defended the title, but he could have a future as a long term midcard title holder. It's not like WWE is always going to book midcard titles terribly. They could have Ambrose re-invent himself as a babyface or a solo heel that has a significant reign as the IC Champ or maybe the US Title again. That could be done as a way to build him up to that higher level because a lot of the time WWE books talents to hold midcard gold before they become main event level performers. A case could be made that Ambrose is past the midcard title level at this point in his career because of how strong he has been booked since he's been on the main roster. However, it wouldn't be a bad idea to put some gold on him so he can prove that he is a credible performer without the help of anybody else.