I've heard a lot of people saying that now John has fixed the wheel, the flashes will stop. I disagree.
Firstly, if the wheel was the reason for the time flashes, why the hell do the Oceanic Six need to return!? It sort of makes the 'come back, the Island is in danger' storyline a little redundant. Ms Hawking says they have 70 hours to return to the Island before something happens. This is after John's arrival and death. So something must still be going off. Maybe something bad will happen to the Island after a certain amount of time flashes?
Secondly, people are saying now John has fixed the wheel, the Island will be all OK and resume it's regular place in space-time. But remember the opening minutes of Season 5-Daniel in the Orchid during the days of the Dharma Initiative. He hasn't been there yet, so the flashes MUST continue after John leaves.
Lastly, people may counter-argue me by saying that the Oceanic 6 don't need to return, it's all just a plan of Ben's. But if you think about it, they've been off the Island for three years. What, did Ben just wake up one day, and think 'let's go back!?'. His current quest was revenge on Charles Widmore for Alex's death. Why would he suddenly want to return? People are also saying he wants to steal leadership of the Others back off John. But they seem to have a mutual respect for each other, and Ben was quite willing to allow John to lead when he turned the wheel in the Season 4 finale.
If you disagree with me, don't go crazy. If I'm wrong, fair play. I'm merely pointing out why I think some people may be wrong about what's happening. Please discuss.