This month I’ve worked a bit on HourGlass 1.5. So there is still hope a public release will eventually happen. The multichannel/surround stuff sure has been a big mess to implement, with bugs and CPU performance problems popping up at every turn. However, with some private testing generously done by Jean-Marc Duchenne with his extreme multichannel audio system (with dozens of channels and loudspeakers), some of the problems have been at least partially fixed.
The longer term plans definitely involve rewriting HourGlass from scratch, based on JUCE. Using the rather ancient Qt4 toolkit is beginning to feel quite miserable, but I will grudgingly persist in getting a few versions of HourGlass 1.5.x done with it for now.