The truth is we have SKY to thank for all the HD channels we have available on Virgin today. SKY have been driving hard for 2 - 3 years to launch as many HD channels on their platform as possible. Virgin, until recently, didn't really do much in the way of delivering HD channels however they couldn't allow SKY to continue unchallenged.
Put it this way, if it was the other way around and SKY decided 2 - 3 years not to invest in HD and allowed Virgin to build their HD folio first before challenging, both SKY and Virgin customers would still only have BBCHD!
SKY, making Virgin better