Got a reply from Pipex and it is now possible for existing customers to upgrade, doesn't say so on the web-site though, still says coming soon
Now i'm really undecided on what to do, go with Vodafone for a cheaper option or stay with Pipex who I have had no problems with, keep all my email addy's, webspace, get up to 8 meg, free phone calls but still have to pay BT line rental, might save a couple of quid in phone calls at the most