Will likely be in the shop today. The manual / documentation is also available on the Steinberg website.
If you have activated C12 in the Grace Period, you will already find the download code for the C13 license in your account and can already use Cubase 13
Owned a 12 License from release so im not in for a grace period. Downloading now so im guessing this is just a demo for now and like @anboithrinciuin says it probably will be in the shop today.
I’d iamgine it won’t work without a license. Even the demo requires a license to run.
Do you see this in your D.A?
I haven’t checked yet but I’m guessing if you try to run the program it’ll show a “no license detected” type error on launch. I could be wrong.
Im guessing this will give an option to activate the demo else is pointless being on the D.A app
Daaam hope you are wrong. 
Having a demo from day one would be even better. Do it Steinberg . Impress us.
Steinberg usually releases demos around 30 days after the launch of a product. The initial leak on their site in September would indicate this is the same when the leak said “The Cubase 13 trial will be available soon”.
In other words it pays to buy Cubase , never use it and your the first for the new version when near release , BIZZZZZAAAARRRRAAAA
Oh , i get it , Steinberg deposits the licences but we wait for the American shop to be open now aahhh ?
With that said, you may be able to get a 3 day free trial from today on Splice. As it appears it’ll be a day one release there and they do offer trials, albeit much shorter ones.
Whats New for C13 is on their site with Dom Sigalas videos running through new features:
Plus release notes which contains grace period info (aug 23rd):
Shame the full details aren’t in there yet though.
It allows you to buy C13 Artist only for now, Pro and Elements links don’t work 
Ahh now, this wasn’t working some minutes ago.
Updating the website on dial up 
yes yes yes
I was giving up hope as I thought it would be yesterday.
I have the week off and for the first time since I was a child I’m bored.
You can buy all versions now, who’s going to be the guinea pig on a C12-C13 update then? 
Just bought the pro 13 update…went through smoothly on the site…just downloading now.