All the E90 based cars have xDrive (same as X3, 04-06 X5's).

E46 cars have the old X5's 4 wheel drive system, which consists of a permanent 60-40 split.

The xDrive E90's should be a lot more competent than the earlier xi models.

Also the new E92 coupe, is the first time in BMW's history that a coupe has been offered with 4 wheel drive...