The F32 4-Series has a two inch longer wheelbase than the F30 3-Series. It also is 1.7 inches wider with half an inch less height. This lends to a more aggressive, sleeker, and sexier looking car.
The drivetrain lineup will no doubt mirror the F30 3-Series. The question is if BMW will go with the 440i or 435i name for the model using the N55 3.0 liter turbo. In the 3-Series the model is referred to as the 335i so it would be odd for BMW not to mirror this although this same motor also get the 40i treatment in other models such as the 640i. Time will tell, for now enjoy the photos until we get the official production model sometime next year.