Sorry if I'm coming in here brimming with negativity, but it's never fun to wake up in the morning and see issues like this.
The notarization requirement is bad enough as is, given that, in my opinion, it adds essentially no additional security to the platform, especially since there's already been
at least one case of malware fooling Apple's notary into notarizing it. (Why not just check a quarantined executable for malware client side, rather than use a notary?!)
But the fact that the notary service can't maintain consistent uptime just makes it painful. I can't send a build to a client now.
Strangely
Apples system status page still lists "Developer ID Notary Service" as green.