Anyone noticed that in volume 1 episode '5 years later', Nikki was still alive and Nathan was dead? Also when Peter fought Sylar, Sylar said, ' When I killed Nathan, he was betraying his own kind.' In the episode 'Powerless', he was kind of betraying the heroes by telling everyone their secrets and got shot. I think it's true when they said, 'The future IS written in stone'. I mean, Tim Kring said that Mika's story would soon end. In episode '5 years later', he was dead right?

That future will no longer happen though as Peter didn't blow up New York.

Sylar killed Nathan and took his place as president. As New York was never destroyed; Nathan will not become president and so anything from that episode should not be used as a template for whats to come.

Due to the writers strike I don't think they even know who is dead and who will survive just yet I think they might even be waiting for fans feedback 1st...

I think the future WILL happen as you can still make it happen. I don't think Isaac's/Sylar's painting will fail. It might not have happened then but it will soon. Just you wait.

Doubt it.

Issac predicted the explosion.

Hiro saw it happen, when he went to the future.
Since it didn't happen the way it was predicted, it probably won't happen.

We've now seen 2 possible futures, both of which have twarted.
So as for those future episodes, where Nathan is dead, and where 93% of the world is dead, I think we can say they're still alive.

i think that it is possible that a few factors are written in stone i mean if you plug in this to the missing factors it makes sense.