I haven't seen any hard case options for the LiveWire, but I have seen concepts that 'should' work based on similar pillion/swing arm set ups. Shad makes a set for the Ducati Diavel, and I've also seen some Givi rack systems for Yamaha sport bikes that seem like they could work on an ELW. I reached out to both Givi and Shad and they both said they haven't made anything for the ELW and they don't advise putting their products on a bike that they weren't specifically designed for.
So - if nothing else comes along this season, I'm going to talk with a few local machinists/millwrights that fabricate all kinds of metal assemblies. Maybe we can come up with something open source that other ELW owners could use. I just don't want it to be butt-ugly since the bike itself is really gorgeous (in my opinion).