I guess, it will be as usual:
nothing
a picture of a B738 at a gate for 30-45 minutes
a picture of a B738 pushed back for another 30-45 minutes
a picture of a B738 on taxi way for 30 minutes
a picture of a B738 at the runway for 15 minutes
Shop opens
Everyone buys at whatever price is asked (forgetting everything they moaned about earlier)
Everyone waiting for the license server to send that key code which will take up to 1.5 hours as it cannot handle the demand.
Tomorrow, everyone will have their shiny new bird and will be happy.
This time, when they announced 18 DEC 1700z, I knew I will skip those steps and buy it on 19 DEC without any stress, if it is not out until 1900z. I would not be able to take a flight anyhow any later than that, so no need to stay and wait or even purchase it then.
Nevertheless, all the best of luck and patience for those who wait after that. I have zero problems of being proven wrong if this means you all can enjoy it earlier.