I'm just assuming DHCPv6 is not supported, and so I put in the enhancement request. In the mean time, if it is NOT supported, I think customers would appreciate the datasheet saying so.
The IPAM team has been pretty good at following up on other requests - they added pulling neighbor tables from devices whose SNMP MIBs support that. Alas, many, if not most Cisco devices do not support it.
If SW could get neighbor tables via SSH, that would be sweet! It's a lot to parse - and NX-OS doesn't even put each entry on its own line! It's like Cisco is trying to prevent IPv6 from happening in the enterprise.
So for now, IPAM for IPv6 really doesn't do much more for us than a spreadsheet would. There's mumbling about InfoBlox doing it all ... for a price.