Must admit I was there. True with 40,000 cyclists on 9 miles of road I bearly broke 10 mph (and most of it was dual carridgeway), the event was clearly a 'fun for all the family' day so I agree not many more people will sudden;y be riding to work. I went because it is the first time I've managed to get my girlfriend out on London roads and like Chris L she was surprised by how friendly they felt (there were group rides to and from the car free section).

As for tax breaks, they already exist. If your employer is willing to sign up to the Ride2Work scheme you can get up to a £ 1,000 bike as a tax free transport benefit (and since it's done through salary sacrifice that's up to a 40% discount).

London is pretty cycle friendly and is getting more so as car drivers learn to expect cyclists to be part of the traffic. If we could get rid of the bendy busses again then everything would be great.