I just had another idea regarding patching X and Y regarding new Mega Evolutions. Maybe, just maybe, we all saw it way to complicated? As far as I know X and Y writes atleast something on the SD card while you save right? What if they coded X and Y in a way where additional Pokémon data can be just "plugged in"?
Lets say I trade my (Mega) Kyogre back to X, maybe OR/AS could just sent the relevant data-files along the trade to the receiving 3DS?
I know I probably spent waaay too much thought and energy on this issue aslong as we aren't even sure if we get new Mega Evolutions but I just like to think about technical issues and how to solve them