I found this very interesting
With the addition of a successful implementation of transaction locking, it becomes possible to move up the target block time to 10 minutes or more. We propose changing the confirmation target to more than 10 minutes to reduce the amount of long term size of the blockchain while utilizing the instantaneous transactions described in this paper.
By utilizing longer confirmation times for noninstant transaction Darkcoin will gain a much smaller footprint and avoid following the path of Bitcoin in the years to come.