My strongest incentive for implementing IPv6 at work is that Gmail is advertising MX hosts that have both IPv4 and IPv6 addresses. So on systems which are IPv6 capable, and where your OS either picks a random IPv4 or IPv6 address or prefers IPv6, you'll end up getting lots of noise when it tries IPv6 and fails and falls back to the next address if you don't have IPv6 connectivity set up.

Could of course just ignore that, but it's a good low pressure reminder to get around to sorting out IPv6...