I think for me to be interested it really needs a set-top box with recording features, I use a projector for all my TV viewing so a new TV is not really an option (though 110" TVs are getting cheaper...) I also have basically not watched live TV since around 2000 when I got TiVo, so if it only does live TV it is kind of pointless to me personally.
I currently use Plex as a PVR which has a standard TV style EPG but uses a stream rather than a broadcast, with the stream coming from a HDHomeRun Freeview tuner which converts the incoming Freeview signal into a stream that I can access from any device on my network (with a suitable app), so in theory if a system like that could just access the Freely stream rather than needing the HDHomeRun and Freeview signal then that would be ideal, but I can't see that happening officially, hopefully someone will find a way though!
I currently use Plex as a PVR which has a standard TV style EPG but uses a stream rather than a broadcast, with the stream coming from a HDHomeRun Freeview tuner which converts the incoming Freeview signal into a stream that I can access from any device on my network (with a suitable app), so in theory if a system like that could just access the Freely stream rather than needing the HDHomeRun and Freeview signal then that would be ideal, but I can't see that happening officially, hopefully someone will find a way though!