There are CF hoods offered by Arma Speed and RKP. I couldn't find the weight figures of RKP but Arma Speed says it provides ~20lbs weight savings (9kg vs 18kg). Not sure if I like how it looks though. I will probably wait for BMW to release a CS or CSL model with CF pieces and retrofit OEM parts. You can also go for aluminum front fenders if and when they are available (on CS/L) but not sure it's really worth it.
Btw, there are conflicting weight figures across the web. On BMW Belgium's website,
the weight of outgoing M2 is reported as 1570kg 6MT [1595kg DCT] while
the weight of M2C is reported as 1550kg 6MT [1575kg DCT].