dig AAAA theregister.co.uk
Still nothing. Coming on to 8 years of me saying this now. It only took 6 years to get SSL'd, though.
And the bit about running dual-stack on everything is a nonsense. What you run internally makes absolutely no difference at all. Sort out your edge first, so you can talk modern protocols OUT. The inside bit literally doesn't matter as you'll never run out of addresses or see any IPv6 advantage on an internal network, unless you literally have 16,777,216 devices inside your network (the limit of the 10.0 ranges).
To my knowledge, there's not a single piece of software that *demands* IPv6 internally all the way to the net. However, it won't be long before websites *demand* that you access them over IPv6. So all you need is your edge/gateway/router/proxy to support IPv6 and translate / proxy accordingly (gosh, if only there was a technology that could perform Network Address Translation.... oh, no, sorry, some fools condemned all that because "IPv6 would fix it all"... all that stuff that's not actually broke...)