It's worth pointing out that this service will benefit the City not just the Wharf. It's about 20 mins on the DLR from Bank to London City, with services every few minutes. I'd favour that over battling accross London to Heathrow in a cab, or tube or cab to Paddington then Heathrow Express. Much less hassle. Add in the ease of the whole London City "checkin and depart" experience and I would imagine this route will be extremely popular by the time it comes in to service.