I have uploaded alpine-1.9.0_alpha4. Available here:
This iso contains an initramfs image that can boot from harddisk. So far
only ext2/3 are supported and extlinux needs to be used.
I fixed the boot from USB directly after uploading the iso image so
copying the content from http://alpine.nethq.org/alpine/v1.9/boot/ to
usb should be able to boot from USB.
There have been alot contributions on building the packages so there are
many more packages that I expected. We now need to do some quality
checking on those. So please test and report back issues.