Hi,
the *tentative* images of Tails 4.0 are available:
https://mirrors.wikimedia.org/tails/stable/tails-amd64-4.0/
They're fresh out of the oven and did not go through our usual quality
assurance processes yet.
Please test and report back on this mailing list :)
If everything goes well, 4.0 should be released on tomorrow
(Tuesday, October 22).
Cheers,
--
intrigeri