If you're not seeing AAAA records for Google's main services, then your DNS resolver might be blacklisted. It seems that Google tries to measure the penalty IPv6 imposes on their users and employs retaliation if it's not happy with it. Sadly they won't contact the affected networks and just stuff the address onto this list. There's also no rationale why that happened. It seems that one can ask google-ipv6@google.com and get a reply, though.
It also seems that this list is perused by other entities like Akamai and Facebook, because people on the blacklist report that the AAAA records of those providers vanished for them, too. The whole discussion thread can be found in the ipv6-ops archives.
