Hm... so... a lot more ponies... so? Celestia gets more people to rule over, also us bronies can unite and take over Equestria... that is if y'all want to,
But anyways, if we were to only he able to be in ponyville... or canterlot or some crud like that... then it would suck, but if we were able to go to other kingdoms/empires/provinces,etc then it would be fine,
But then again... there is always the population overgrowth, Welp BUILD MOAR FARMS, more food Yay!
Also the fact that we could be sent to the moon,set in stone, banished or like got a giant spell that sent you team rocketing out, or even KILLED
Eh... also there are over HUNDREDS of crazy OCs like those OCs that are always sad and kill people that kind of stuff so the crime rate in Equestria will go up