Sadly it seems the purchase of StreetLite's and StreetDeck's is actually happening, or at least the StreetLite's are, as they are supposedly due to arrive at Darlington in January.
I really can't predict much else, although one thing to consider is from next year, the Whitby Park & Ride contract will require buses no older than 10 years old, so you are either going to need something new or cascades from somewhere, VDL Gemini's or E400's maybe? That's assuming Arriva win the contract again or even bid for it although I imagine it will be Arriva operated again.
Arriva North East: Order Predictions