Get what you like most.

Personally, I like the looks of the current 3 series a bit more than the E90. But that is only my opinion - I am sure the E90 will grow on me. The current car is also fairly well wrung out - meaning - not much in the way of bugs as compared to the 1st year design E90.

If you can wait (and evidently you can) - drive the E90 demo back-to-back with the E46 330 - see what screams out 'buy me'. I would THINK that the current 330 may feel a bit quicker than the E90 325, but that is yet to be seen.

Good Luck