This is the third year in a row that sees IPv6 adoption growing exponentially, with a factor a bit over 2:1 year-on-year (2011 -> 2012 -> 2013). Since we're in the early deployment stage, this trend can be expected to continue for at least several years (and maybe with an even larger factor), such that by the end of 2015 a 10% IPv6 penetration is most likely a conservative estimation.
The IPv6 penetration, even in low numbers, is important for this project because IPv6 can be used to do the
heavy lifting in the routing ring, such that the more IPv6 connections
are deployed, the less the bandwith strain on the routing