As it pertains to Scotty...I don't believe he is dead. I think we'll see a novel where he somehow escaped and is marooned somewhere (a planet? ship?) where he is healed and not on the brink of death.
Of course Scotty's not dead. He still has to cut the ribbon at the Montgomery Scott Engineering Sciences Building at Starfleet Academy on his 200th birthday in 2422 as per Engines of Destiny
. That's the future I'm believing in at any rate.