Semi-expected, but still disappointing
When Pokemon Omega Ruby and Alpha Sapphire arrive, it won’t bring any new Pokemon types, per se as it pertains to the Pokedex. It will have new Mega Evolutions though, which can be achieved by way of holding certain items and initiating a transformation.
Sadly, it was confirmed that these Mega Evolutions will not be supported in Pokemon X & Y, whether it’s by way of a transfer or in the base game itself. If you want to experience the new evos, you’ll have to just do it in Ruby and Sapphire.