This was the response I received back in November when enquiring about new hardware:
"We are indeed currently working on the next generation of receivers. After all, developing new equipment takes a lot of time.
However, this also means it is still a work in progress, and as such, we can't provide any additional information at the moment.
We will make sure to inform our customers when the new generation will have a release date, therefore keep an eye on our website!"
So there is at least something being worked on (which I would expect as the current 6xx series - whilst perfectly serviceable - are not quite in the same league as the whole-home PVR's and X1's of this world).