http://www.cableforum.co.uk/article/...-virgin-mobile
Well that explains why NTL and Telewest had not announced what the combined company was going to be called. These merger deals are typically many months in the making so they would have definately have known about it when they announced that NTL and Telewest were merging.
I think that calling the combined company Virgin is a good step to take as it neither the NTL or Telewest brands have UK-wide recognition and for those or any other new brand they would have had o launch a huge UK-wide publicity campain to promote the new brand. But with Virgin they will not need to do that - it is already an internationally recognised brand!