The US should take the initiative and just like the digital cable switch for cable providers, require Internet Service Providers to completely deploy IPv6 on their networks so that all home (and likely business too) users have access.
The reason is that IPv4 does not provide enough space for the continued growth of the Internet and that ISPs are easily tempted to "cheat" with things like carrier-grade NAT instead.
The date should be no later than about 2020 (otherwise, full adoption is expected in the late 2020s).