Jokes:
no money left for bacon
buffalos will raid them
they have realised, after all this time spent together, they actually hate eachother
Rarity got pregnant from one of the livestock
Twilight has to go to an asylum
Rainbow Dash will trun back to ford every river in North-America
Pinkie starts a red light district
As soon as Applejack sees a rainbow, she will go back to Ponyville
Fluttershy, disheartened by the brake of their friendship, commits suicide