The only areas where this would catch on are high density locations in the US.And this is why the US is and will always be behind in public transportation. Actually I could see something like this catching on more than buses in the US.
http://www.atsltd.co.uk/I would love to ride those but I believe they have many flaws that might ultimately relegate this concept to the archive of brilliant yet impractical inventions. I would much rather like the work on maglev trains resume. And, for a company that reportedly got a rather impressive Heathrow contract, they could come up with decent branding and corporate identity, especially coming from a country with a dozen railway companies with branding leaving P&G to shame.
This would be great in New York. I'd love to see this replace the LIRR.