Unless your goal is huge enlargements of exhibition/museum quality, 18mp is plenty of info. I have personally seen and made 16in and 20in enlargements that are crazy good from 12 to 18mp cameras. Most books, magazines, newspapers and the like, certainly don't need or even want these enormous file sizes. It's overkill. Portraiture, weddings etc.. have been done on far less megapixels for years! So most money making photography needs will be fullfilled with ease. Those who need more camera, simply buy more camera.
High dynamic range, noise/ISO performance, color accuracy, FPS, focus speed, accuracy and tracking, ease of use, user customization, durability, reliability are all far more important than megapixels alone. I think we may all be in for a real treat if they do in fact produce such a camera!