@Symon
I agree that cycling is a positive endeavour, I just don't agree that putting unwary, casual cyclists into some of the world's busiest roads is a good idea. In my experience the cyclists in London generally are good and know what they're doing. Anecdotally, I see more cyclists waiting at lights than I do jumping them. They also stay off the pavements.
The initial users of the new cycling scheme that I've seen, seem to believe that they're in Lark Rise to Candleford, cheerfully interacting with pedestrians. I honestly believe they will exacerbate the bad name cyclists get from other road users. The Netherlands are a good example of cyclists as major road users, my concern is that London is not Amsterdam - in Amsterdam it's the volumes of cyclists that encourages respect between drivers and cyclists - that just doesn't exist in London, perhaps it will come.
I should qualify myself by saying I cycle regularly, consider myself a good cyclist, don't drive regularly at the moment, and recently left London. I also accept that wearing a helmet will make little difference if I go under a large vehicle, however for the lesser incidents, such as coming off at 20-30mph and hitting the ground, it can make the difference and lessen the injury.