Here's the "What If..." scenario I always wondered about. What if the Stardrive section blew up, but the saucer never crashed. Would Starfleet have built or given a new stardrive to Picard for the still space-worthy saucer? Would that be considered a whole new ship (i.e., would it still be the D, or would it get renamed to the E)? Conversely, would they have scrapped the saucer for parts and pushed out the Sovereign Ent-E anyways?