Then, of course, as mentioned below, Riker could have been offered command.
I wonder how that would have worked out. In the timeline of the movie (as I understand it) Riker had already been offered and had accepted the command of the Titan before the beginning of the movie. Picard mentioned this in his wedding toast.
So, if subsequent to Picard death Starfleet had gone to Riker and gave him the option of the (presumably) more prestigious command of the Enterprise E, what would Riker do? Enterprise or Titan?