In 4th Edition, There is no Monstrous Manual. All monsters are sold via randomly inserted plastic D&D Mini's boxes. These Mini will be a different scale of the older D&D Minis. To alleviate confusion, These D&D Minis will be called D&D Miniatures: 3rd Edition.
Spells will no longer be printed in the players handbook, instead they will be printed on cards and placed in randomly assorted booster packs. These spells will be labeled D&D: The Gathering.
Finally, There will no longer be a PHB or DMG. Instead players will need to register with WotC fan website Gizfoobo, which for only $15 a month will allow players access to the complete ruleset. Players can purchase additional feats, skills and classes as an electronic download, similar to how players purchase e-books now. However unlike normal PDFs These books are loaded with DRM Crippleware and will only work on Windows Vista.
I heard it all from an "inside source" at WotC. Its all true. every word. Because this is written on the internet. and the internet never lies.