Unfortunately the 'brains' behind HS2 was never going down the Maglev route, their reasoning being incompatibility with existing technology ( well duh !) .
HS1 could not be - read - not have the funding for - upgrading, and there really has not been any viable proposal for a single backbone from the far north to the south and beyond.
Practical reasoning kills off the idea because of the faster speeds attainable over long - 150+ mile - distances means any stops in between, cancel out the journey time savings.
Effectively the country isn't long enough and there is little incentive for anyone to swop one hub system already in place - flying to Heathrow/London City, for another where there would be only one terminus in the highlands, which could really only be Edinburgh.
Ultraspeed did have a proposal, with some nice technical snubs on existing wheeled livery, the noise pollution reduction and the pylon/elevated sections eliminating much of the need for land reclamation and compensation, but it was a dead duck thanks to the whole point of commuting, that of turning a profit for the shareholders in a privatised world.
