When it was first revealed that the Superhero Registration Act was being renamed the Sokovia Accords, it was assumed Marvel were swerving registration in legislation relating to control: when a superhero could be sent to another country and what they were allowed to do. Boring, and less catchy, but it made a lot more sense in the wider context of the MCU, because convincing a U-Turn would be remarkably difficult. But it looks like Registration remains a big part of the Accords: their front cover has the sub-heading "Framework for the Registration and Deployment of Enhanced Individuals." So the suggestion is that the government wants to take a roll-call of all of the superheroes operating in the world, in the interest of control and accountability. It's still more likely that Bucky is a bigger driving wedge between Cap and Iron Man, but the confirmation of superhero registration is a massive one - as much for the problems it causes as the intrigue. And the suggestion is that superheroes are going to be underground or enforced heading into their Phase 3 movies.