IPv6 is very much in vogue at the moment. test-ipv6.com is a useful site you can visit that tells you how prepared you/your connection/your ISP are for IPv6.
I’ve run some tests on two connections for you to compare the results. One is IPv4 only and the other dual stack IPv4/IPv6. The difference is self explanatory.
The site itself will tell you that the most important test is the Dual Stack DNS. If this one fails or takes too long then you will have problems once people start rolling out IPv6 only sites. Clicking on each image will bring up a larger version. Both sets of tests come from Timico connections – the one on the left is dual stack and the other IPv4 only. Also click on the header of this posts if you want to see more of the successful test results.