The production version of the BMW X4 looks very much like the X4 concept that was revealed a few months. The exception to that are the expressive fascias and fancy wheels. It has the same roofline and looks very much like it will be fitting in place as the baby version of a BMW X6.
It shares that platform of the X3 but is lower and wider. It will be a bit more upmarket in the way that the X5 and x6 are. Rumour has it that this could mean that the X4 will not have the base engine of the X3 so that it is sportier but it will leave room for an M version later as well.
BMW has already stated that it will be showing the 4 Series coupe, Refreshed 5 series, i3, next gen X5, Concept Active Tourer Outdoor and X5 Concept eDrive plug-in hybrid and so it seems the X4 will not be there. However from the images and how finished it looks, it is expected that it will appear at Detroit or LA.