Great news Ian! Congratulations and kudos to you!
Do you consider the convention exclusives, sketch covers, multiple covers and second and third printings official DC releases, or does owning one copy of each comic count? Just wondering because all those Infinite Crisis books alone make the mind boggle.
Also, have you considered putting the collection on display at a museum for a limited time? What about a digital archive of the covers? It would be a monumental task to scan all those books, but what a great resource it would be! I think you should strike a deal with the Photojournal Guide people to do another series of books based on your collection.
Finally, would you ever consider selling the entire collection? I bet you could get at least 10 million for it...