A few months ago I had the mates rates package for phone, TV with V+ and second V box and 20meg broadband i.e. the original VIP packages. I was able to upgrade to a TiVo box, and 50meg broadband i.e. the more recent VIP and retained mates rates, albeit at the higher pricing. It proved just to be one call to customer services and India sorted it all out

But maybe, it was because I was effectively adding new services by upgrading that they could do that and I suspect these packages / offer terms do change from time to time?
Oh and for anone reading this not lucky enough to have a mates rate deal, don't PM VM staffers on here asking for one. Your mate will already have offered you this facility if you are a genuine friend or family member.