For application developers, you can use the 48beta branch of the flatpak runtimes, which is available on Flathub beta.
Also, an installer image is available for testing and porting extensions.
This installer image is meant to be installed in a virtual machine with EFI support (such as the GNOME Boxes version available on Flathub). You can also try to install it on bare metal.
Thanks to everyone involved and please give it a try!
WARNING! This is beta quality software. This release is intended for GNOME developers and beta testers. For more information about the 48 release, the full schedule, the official module lists and the proposed module lists, please see our schedule page.
No: the gnome-shell-extensions module has been removed from core. The extensions are still maintained, and released alongside GNOME Shell, but they are not part of the GNOME release any more.