The "Final Cut-Off" deal between publishers and Diamond Comic Distributor lets retailers change their orders up and down, closer to the date of publishing, allowing for more acurate orders that reflect the marketplace better. You'll see the results in BleedinG Cool's regular look at advance reorders. Publishers such as Marvel, DC, Dark Horse, IDW, Image and Oni are participants in this. Today at the NYCC, it was announced that Dynamite and Boom! would also be joining the program.
What does that mean. Well for publishers, they can promote closer to sale date, for retalers they can respond to topical changes more quickly and for readers an easier way to get comics that they suddenly become interested in a few weeks before they go on sale.