In a recent interview that Geekr8 held with Niantic CEO, John Hanke, in which he dropped a hint that there may be a possible migration of the region restricted Pokemon! They translated Hanke's quote from German, which stated, "Some monsters (Pokémon) only live on certain continents – maybe there will be a migration someday, the Niantic CEO indicates."
If you are unaware, or have forgotten, the current set up is:
North America - Tauros
Australia - Kangaskhan
Europe - Mr. Mime
Asia - Farfetch’d
Equator - Corsola and Heracross
This is going to be great for all the trainers who are still out there hunting! If they do the migration once, they will likely do it again, which means that we traveling the world will no longer be a requirement to complete our Pokedex's. Better catch 'em all before they find a new home!