Charging for bags won't work. Had the dubious pleasure of having to fly Ryanair recently and some of the trolley bags that were being taken on were taking up more than half an overhead bin - and that is before the charge has been implemented!!!
Ryanair are hot on leaving on time if not early but I can't help but feel that this new scheme will back fire on their punctuality record. Probably on most flights there will be a lot more cabin baggage than normal and it is not going to fit in the bins or under the seat so then the bags need to be tagged and taken off and placed into he hold - thus taking time. Does the passenger then have to be forced to pay for his bag to be placed in the hold - It is Ryanair after all!