Wow he signed the address that can prove nothing thats perfect, hold on let me open Bitcoin-QT I can do the exact same thing by creating new receiving address and signing it,
Of course anyone can create and sign an address, I do not expect this to do anything until the point that mining starts. However I figured it was best to have it done before mining starts just to 'have it done'.
To be crystal clear- The mining pool and the user name will be public info and we'll all be able to see the hashrate directly for ourselves.