What about skipping X7, and offering X8 instead? A sporty crossover SUV instead of XXL utilitarian SUV ala GL, Escalade etc.
X8 will be large enough to be more practical than eg. X6, but luxurious & SPORTY - DYNAMIC in shape as well. There are enough utilitarian large SUVs out there (Range Rover, GL, Escalade, LX, Bentley SUV coming etc) ... IMO X8 would better fit BMW image, and it will be unique again in its size segment. And it can be placed on extended new X5 platform - since the platform will be modular. And for those who want more spacey SUV - X5L with usable 3rd row seats can be offered. It will cater US market well - while other markets I guess are not much interested in large utilitarian SUVs - since elsewhere large SUVs are more image vehicles, than used for practical purposes. And in those markets (China, Russia, ME etc) X8 will fit well.