If you weren't lucky enough to be near one of the Wizards WPN stores, you can now get your shiny new D&D 5th Edition Dungeon Master's Guide from your local game store, bookshop, or online retailer of choice! That's right - the street date is here, and the DMG is now widely available! And it's worth it - the book is trending at 94% right now!
Additionally, WotC's Jeremy Crawford gives an interview at Polygon about the new DMG.