What if Dean had said yes to Michael?

[heard_the_owl]

I know that the angels promised 'heaven on earth' if Dean would become Michael's vessel and also that there would be many casualties in the war, but what do you think the world would be like for the post-apocalyptic survivors if Michael!Dean defeated Lucifer?

Any input at all would be appreciated, including links to any discussions on this topic.  And thanks so much in advance!