All the fleet are to be A320s. 35 more from next year and then the huge tranche of NEOs from 2017. The A319s are on the way out, rather than the fleet expanding much.
Which makes sense as they were the wrong choice in the first place. Fuel consumption is about 120 kg lower than the A320, but with the same number of cabin staff and 30 fewer seats.
Plus EZY bought the low-MTOW A319 which affects resale value; extra range is normally the A319's attraction. Ooops.
And of course the sharklets improve performance on short routes; even the 1% saving they offer on a 200 mile flight is beneficial.