For the first time, X7 has been spotted on public roads in Germany. It is huge and mean. BMW confirmed using a wide variety of engines, not just ones in X5 and X6. Some sources are mentioning a possible usage of the new version of N74 V12 engine already used in M760li tuning out crazy 610 hp. I imagine the name would be something like X7M60i. Try saying that ten times as fast as you can.
We can also surely expect hybrid model because of the sales associated with other models. With that being said an X7 platform is not extended X5 or X6, but it will have bespoke parts for a new car. It will come in two versions, more entry level three-row seven seater type and more luxurious four-seat "ultraluxury" type of monster.
Its production is set in Spartanburg in the US. The sale is predicted in 2018. Before it was seen on the road, BMW was testing chassis mule based on a 7 Series. It wore heavy weights on its roof to replicate centre of gravity which is much higher in X7 than G11 7-series (seen below). Check out my QualityCar tribe for more car stuff.