I used Fedora-Workstation-28-20180402.n.0.aarch64.raw.xz and can boot
successfully on my Raspberry Pi model 3B-plus. I used:
fedora-arm-image-installer --target=rpi3 --media=/dev/sdi --norootpass --resizefs
to prepare a new SD card, but the root file system was not resized. I
had to do that manually. A dtb file for the 3-plus is already in this
image, there is no need to do anything about that.
There was some hesitation early in the boot process. (Maybe fsck? Maybe
some First Boot procedure timing out, or perhaps some parameter-setting
activity - there was something that looked like a text menu but it
disappeared before I could read it.) It lasted around two minutes.
After boot, I logged on as root, created a user, enabled sshd, and can
now connect to the machine using ssh.
Note that before I booted the system, I changed the default target from
graphical to multi-user, in order to avoid gnome-shell troubles:
I suspect the wired Ethernet port is not operational (I used a USB
Ethernet dongle for my ssh connection.) I have not tried any wi-fi
"dnf upgrade" wqs successful, and updated 60 packages.
There are problems, but a lot is working. Certainly enough to make
it reasonable to explore and learn what needs work.