Dominion: So I uhh... I called it again.
Back when they removed Dominion, I read between the lines of their announcement journal and predicted that it might make a resurgence in the future as a rotating game mode like Hexakill and the others. They implied that it might make a return as a temporary game mode as soon as they sat down and refined the game mode's rules or something.
Cut to half a year later, that's exactly what they're did, that's exactly what they're doing, and that's exactly what will happen.
While we're on the subject of rotating game modes, how about a return of the Bilgewater event, Riot?