9. Fate Of The Romulans
The Romulans are one of the Federation's oldest enemies, going back to the era of Archer's struggles with a conspiracy to 'reunify' with the Vulcans with them to Sisko's cooperation with them on the USS Defiant. The Romulans have truly remained a threat and notable presence in the Alpha Quadrant in their tense relationships with other powers such as the Federation, the Klingons and the Dominion.
Upon the conclusion of the Dominian War, the Romulans and Federation were engrossed in a cold war that threatened to bubble over when Shinzon ambushed the USS Enterprise-E. When this conflict was resolved, there were hints that peace could be achieved. This was put to a test when a supernova had caused the destruction of Romulus, which led to the Romulans reaching out to the Federation for help. The fallout of this alongside the Synths revolt in the Utopia Planetia ramped up tensions between the powers.
Season 1 saw the Romulans infiltrate Starfleet with Commodore Ooh whilst the Zhat Vash was working behind the scenes to thwart a synthetic prophecy. This was thwarted by the efforts from the crew of La Sirena and supported by Starfleet by way of Riker. The Romulans then retreated and was poised for future conflicts.
However, there was no mention of the Romulans and the fallout from the events of Season 1. As such, we are still waiting in anticipation for the next saga in the Romulans' story.