In message , at 17:55:13 on Wed, 17 Sep
2014, Mizter T remarked:

This vapourware concept you're so very keen on and contactless in
London - how do you describe it - the gases have now solidified?

It's a product that long conformed to the definition:

"Has been advertised but is not yet available to buy, either because it
is only a concept or because it is still being written or designed."

I'd add the rider that such a thing is especially vapourous if it fails
to meet several announced release dates.

It's taken almost two years to move it on from buses to the rest of the
TfL estate, for example.
--
Roland Perry