Package Hub for SLE-15 shows up on the horizon and is currently under heavy development.
If you are already a beta tester for SLE-15 who immediately wants to get hands on packages from Package Hub, there is an easy
way to test the packages that are currently available.
Since the packages are built in the Open Build Service you can add the repository manually with the following zypper command:
zypper ar -fc https://download.opensuse.org/repositories/openSUSE:/Backports:/SLE-15/standard/openSUSE:Backports:SLE-15.repo
The availability thru the SUSE Customer Center to beta users will follow soon.
Please also note that since it is currently under heavy development, not all packages you might expect to be there are currently available.
They might also not be available to all platforms at this point in time.