After trying to sort it out, I believe that whole fiasco should have shattered the Universe, as I have said in another thread.
Think this one through:
Assumably, both Kirk, Picard, and Soran went into the Nexus.
Picard and Kirk came out, leaving Soran inside while they attempted to change history.
Somehow, there is only one Picard at this point, instead of the two who should have been there.
They sucseed in stoppping Soran, and Soran doesn't go into the Nexus.
One Picard goes back home, one Kirk dies, and one Soran dies.
Questions:
Where is Picard #1?
Where is Soran at this point? At least one is in pieces, but is there still one in the Nexus?
If there isn't a Soran in the Nexus, because Picard prevented both Soran and himself from entering it, why does he remember/live with the ramifications of his time in the Nexus?
Would his stopping himself from entering the Nexus stop him from stopping himself from entering the Nexus?
My conclusion: Picard should have caused a time loop, which would have resulted in the universe ripping in half, releasing energy that would take out several surrounding dimensions at the existencial level. Meanwhile, Picard #2 escaped, and is now sipping martinis in the Mirror Universe.