I find this a very cool site: http://www.worldipv6launch.org/measurements/ : It will show the IPv6 deployment (percentage) per ISP or ASN. This way you can monitor which ISP actually does IPv6 (instead of just intentions and announcements), and how thoroughly.
Results for some ISPs:
Dutch ISP Xs4all is at 19.54% IPv6 usage:
Dutch ISP Solcon is at 6.63% IPv6 usage:
French ISP Free is at 37.16%: