Since it cost GBP 5bn and was sold for 2.1b, I'm failing to see where's the "great news for tax payers and rail users". For the latter, the failure of British Rail privatisation and of the tube PPP maintenance contracts clearly shows that selling out transportation infrastructure is a dodgy bet for the least.
When it works, it usually means giving private companies a nice little monopoly and a steady cash flow -take the French privatisation of motorways for instance, where more is going to share holders and less to building of new roads (which was incidentally the excuse in the first place for instoring tolls on those autoroutes).
But usually it doesn't work, and either companies end up bust with taxpayer having to mop up the collateral damage. Think the great
Plus relinquishing a tool to boost a nation's economy and litterally shape a nation fabric is neither a good news for users. Prove me wrong...