I reckon that an order will be placed in the coming months for the 2015/2016 orders so the new vehicles can be placed into service before the DDA regulations come into place.
I think the Streetlites would work on the 57 as Malarkey suggested. Mainly because the route isn't that long so won't be putting any heavy work onto a light weight vehicle. I think we can also all agree that it is about time that the Pronto gained new buses whether that be direct replacements or replacements through cascades from the X1 or whatever it may be.
RE: Go North East: 2015/16 Financial Year Order Predictions