We have no concrete info. HiMedia aren't being very forthcoming.
If I was going to speculate I'd say that they are concentrating on getting the new Q5/Q10 Pro products out. After that resources will be freer to get out new H8 (and possibly 4K3D) firmwares.
There will soon be a new H9 with slightly higher spec, but based on the same RK3368 platform. They will share firmware so this ensures that HiMedia will continue to support the platform. Not sure whether we'll stock H8+H9, just H8, or just H9 in future. H9 due in summer.