Well, so far no details were announced. It doesn't have to do with the engines in the 2001 models. It is definately a problem but since BMW is very generous about the issue I would be able to deal with that.

I would still buy the M3.

By the way, BMW just presented their new 3.0-Inline 6 with Valvetronic intake system. It is presented in the 630Ci and supposed to appear in the 3-series end of this year.
For the first time they used magnesium for the cylinderhead-cover and the crankshaft housing.