It will need to be activated by central office, how the process this, I'm not sure!
I'm currently 'thinking' that the upgrade might only be available on TV boxes with the 360 software, BUT my word shouldn't be taken on that.
The theory for my thinking this is that Virgin are currently in the long process of upgrading V6 boxes to new version of software called Horizon which will remove the need for TiVo's services and save them a bunch in licensing fee's, what better way to encourage people to make the switch than to dangle a carrot.
It's going to be a waiting game for now until more info is available.