There's an interesting thread on Virgin's own Community Board developing about next year's introduction of Horizon software on existing V6 boxes. Around halfway through a Virgin staffer writes:
Pending successful trials, from next year any existing customers with 2 x V6 boxes will be able to upgrade them to 360 over the air and keep the entire 2TB storage across both boxes.
Some ultimate oomph customers are being contacted very soon to join the trials. We would like to contact all of them but far too many people are opting out of marketing these days.
This contradicts earlier reports that Horizon won't be replacing TiVo on existing hardware. Meanwhile, the ever-reliable Spiderplant on Cable Forum has confirmed that:
There are 3 boxes:
Arris boxes: Can run either TiVo or Horizon software
Humax boxes (with or without a hard drive): Can only run Horizon software
I wonder if existing recordings, series links etc on a V6 are preserved during the upgrade to Horizon? I suspect the answer is no but I'd be happy to be wrong on this.