They need to change their old methodology and I am glad that they are taking positive steps in that direction. Under the current methodology, centralized coins such as XRP (80% of the circulating supply being held by promoters, either directly or indirectly) are given inflated market capitalization, while coins which are more distributed loses out.
My suggestion is to remove the volume that is held outside free-float and in cold storage from the calculation of market capitalization. In the case of Bitcoin, that would mean excluding the "lost" coins (including the BTC980,000 being held by Satoshi) and exchange coins that are being currently held in cold storage. The updated market cap may be lower by 20% to 30% in the case of BTC, and as much as 80% to 90% lower in case of currencies such as XRP.