I hope not! It would be another brick in the edifice propounded by Blunkett, Clarke, Reid and Blair: the database state.
I already have the Royal Bank Switch card. I think all their customers in Scotland have the same sort of card. That can be used for any transaction however small.
My concern is that a transaction with Switch is traceable back to the owner of the card, whereas cash is untraceable. Over the years since about 1500 the Banks have expended enough effort to fill a small museum (which stands at the top of the Mound in Edinburgh) on efforts to make banknotes and currency trustworthy. As long as it is very hard to forge a bank note, the seller can trust the currency rather than the customer. That sounds like a trivial distinction but actually it's really important. It means that the seller can verify payment without knowing who the customer is.
Using Switch involves a dramatic loss of privacy. That's why you can't buy a mobile phone with cash in the UK: the government wants to be able to trace your calls. (It's also why you can't buy or use an encrypted mobile phone at all: the government wants to listen to your calls and read your texts.) And you can't buy an anonymous swipe card with cash: all such cards can be traced back to you.
Once records of everything you buy are being made up by the banks, you can be certain that the government will obtain copies of them (as they already do with records of the Internet sites you visit and the emails you send.) The threat to basic privacy, to do whatever legal thing you wish without anyone else finding out, will be greatly reduced. If you don't think these records will be abused, try counting the number of nuisance phone calls you get as a result of the abuse of the telephone directory, which publishes only the least intimate of personal data about you.
If cash is actually abolished it also means, incidentally, that small traders will need to buy and operate expensive equipment and open expensive accounts, which will give big corporate business yet another advantage over the small traders whom they hate and fear.