And the new Spectre is...
My answer is hardly novel: GCPD Detective Crispus Allen. Why? Several reasons.
1) He's dead. This automatically gives him a leg up over characters who are not dead.
2) He died seeking vengeance, and his death came before he could see justice done. This is, per Ostrander's history of the Spectre, the standard motivation for a Spectre host. Allen was doing his own independent investigation of corrupt cop Jim Corrigan in order to expose him, and Corrigan killed both Allen and Allen's informant to protect himself.
3) The circumstances of his death share a lot in common with those of the original Jim Corrigan. Both were good cops, both were murdered, both murders involved police snitches, and both died in the middle of unfulfilled quests for justice (as described above). This has all the earmarks of recapturing the essence of the original Corrigan's death, and given DC's new editorial direction, it seems far more likely that they would want to return the Spectre to its roots rather than take the character down a radical new road with a corrupt and murderous host in the form of the 'new' Jim Corrigan.
4) When I first read Gotham Central #37, I thought it was perhaps the most worthless issue of the series. It offered up a little on Allen's spiritual crisis, but the rest of the issue was largely disposable. If Allen is truly dead as of the end of #38, then what was the point of #37? Why spend an entire issue that does virtually nothing other than explore a character's inner struggle over religious faith, when you plan to knock him off in the very next issue? Why do what may be GC's first first-person narrative issue if you intend to kill said first person? If Allen is now gone forever, then #37 was a complete waste of $2.50. If, on the other hand, Allen were to survive on in some ectoplasmic form, then this crisis of faith that was introduced would instead be foreshadowing for the sure spiritual conflict that would result from making a man who doubts God into a man who acts as God's agent of vengeance. It's an instant character hook for the new Spectre, along with the fact that he would still have a family.
Although I have been rather negative about IC's treatment of the Spectre in the past, making Crispus Allen the new host of the Spectre would go a long way towards DC redeeming itself in my eyes. It would manage to replicate much of what made the old Jim Corrigan a good Spectre, without reviving Corrigan or copying him outright. It wouldn't be resorting again to the creatively incestuous notion of making a spandex-wearing superhero into God's agent of vengeance. Plus, it would keep a good character 'alive,' albeit in a different way.
So that's my prediction. I just wanted it, and my reasoning, out there before any answers hit stands. I don't make a lot of predictions as to comic storylines, but I feel darn confident about this one.