WWE is under no obligation to punish Swagger at this point, he hasn't been convicted of anything for a start and unless he fails one of their tests then he hasn't "got to be" suspended. They could still give him a World title and say that his conduct since has been exemplary or that he was fined most of his Mania payoff...
One thing that WWE is pretty big on is that individuals have social responsibility for themselves... Rosa was sent home from the tour, but not released, they haven't fired Jey Uso, A-Ry or others with DUI's. Indeed, is what Swagger did any worse than what Jim Duggan did in 87? Lined up for a mega push and caught stoned in a car with your "rival", Hacksaw wasn't fired but depushed from what they originally planned for him and never got near that level again. Vince in particular knows that people in the WWE screw up, it's inevitable and comes with the pressures of the job. Even guys like Marty Jannetty had several chances to make good.
Swagger lost a match he was slated to win and that is his punishment at the end of the day, he knows what could have been and that it wasn't cos he blew it... much like Lex Luger did.
As for the US title, yes I do see that being a logical place for him but there are also going to be others who could use that spot more effectively. Fandango, Chris Jericho, a returning Christian or Evan Bourne v Kofi... all of those guys would benefit more from the US title and fit the title better.
Swagger will likely end up like Duggan did, always employed, always in a relatively good spot but won't get the "intended push" because of the misdeeds.