I'll be interested to see how it works for my situation.
I didn't fly much with KLM/AF in 2011 (had a lot of business in the UK last year) so only managed to earn around 22000 level miles. However I had carried over 117000 from 2010.
Hence at the start of 2012 my account showed 24000 Level Miles (117000 + 22000 - 115000).
Hopefully this will be adjusted to 69000, leaving me just 1000 miles short for Plat again
Or will the carryover be based solely on miles earned during 2011.