What is going to replace the current 4.8is
 

The new 4.8 is taking the place of the 4.4 so what is going to take the place of the old 4.8>?

Pure speculation at this stage, a year from introduction, but how about:

• A sports model with more power, and a much higher price tag
• A model name that is not related to displacement, similar to 335 and 550. Probably (E70) X5 5.0, but not because there are 5 litres displacement.
• No V10 from the M5, since the range would be laughable and the high-revving engine is not suited to this style of vehicle
• A V8 with two turbos, since torque will matter more than hp with this weight. Could be the 4.4 twin turbo that has been leaked in the press, or something larger just to make a brand statement.
• A release date that coincides with the X6 (same powertrain)
• A modified E70 body style, more aggressive.

you don't think the v12 from the 760 has a chance?

No chance. Wait for the X6 with bi-turbo V8.

Seems like we need a sticky at the top of the E70 forum forecasting the 4.8is replacement, since this question comes up very often..