I've been cycling to work since the beginning of the year (first to Canary Wharf, and now to Blackfriars) and going from the numbers I've seen the scheme appears to be very popular. The BorisBikes look ideal for the short hop (station to office - I think the "basket" on the front is inspired), however, I would not want to undertake any sort of distance on one. So I'm not surprised Boris has stuck with his old stead.
What I would like to see to support the scheme, are "cycle proficiency" classes for adults (not sure if they still do them for kids). Too often cyclist put themselves and other road users at risk by not riding with due care and attention. I'll save a rant about vehicle drivers for another day.
As for the cycle to work scheme it is fantastic (though sadly I believe it may be about to be cut), and enabled me to get a very smart Boardman road bike for effectively 50% it also enabled me to spread the balance over a 12 month period. Whilst I'm hoping the "nominal" purchase price will be just that "nominal" I still would argue if it tipped 10/15% as knew this was a possibility when I took out the scheme and have still saved 100s of pounds.
How can you tell happy a cyclist, flies on his teeth.