On Dec 26, 2015 5:45 PM, "Pieter Wuille via bitcoin-dev" <bitcoin-dev@lists.linuxfoundation.org> wrote:
> My opinion is that the role of Bitcoin Core maintainers is judging whether consensus for a hard fork exists, and is technically necessary and safe. We don't need a hashpower vote to decide whether a hardfork is accepted or not, we need to be sure that full noded will accept it, and adopt it in time. A hashpower vote can still be used to be sure that miners _also_ agree.

To clarify, that's the role of Bitcoin Core maintainers because they decide what goes into Bitcoin Core, not because they decide the consensus rules of Bitcoin. Other full node implementations (say, libbitcoin) will have to decide on their own and Bitcoin Core mainteiners don't have any authority over libbitcoin (or other alternative implementations). Nobody has such authority (not even the creator of the system if he was still maintaining Bitcoin Core).