Steve knows. Some internal developers know. Maybe many people more. Some say 8A428 is GM - but that build was rumoured to be released internally. So no definite information until it arrives...
If I remember correctly, there was similar talk with Panther, and some people thought it just couldn't be that 7B85 would become GM - yet it did. (Which'd lead to suspecting 8A425 could be GM.)
If I remember correctly, there was similar talk with Panther, and some people thought it just couldn't be that 7B85 would become GM - yet it did. (Which'd lead to suspecting 8A425 could be GM.)