Well Vueling certainly seem to have big plans for Luton, targeting existing EZY routes which hopefully means competitive fares and better choice of flight times - the latter certainly seems to be the case with the 3 routes they've announced so far.
EZY had better watch out, there's still plenty of room for Vueling to grow at Luton, especially outside of the peak hours which actually suits them fine since aircraft aren't Luton based.
Hopefully we will see more EZY routes announced before long or maybe their approach should be to operate some more Luton routes as they do with MXP and use aircraft from other bases? An example is AMS where they could now operate a first in, last out flight as Vueling have done with their flight times.