Welcomed into the bosom of the enemy with open arms and no questions asked. Even on PvP servers where the ganking of opposite faction players is the norm and hostilities should be at their peak, thanks to faction changes you now have the option to play both Horde and Alliance.Another smaller but important issue I can see happening is those who choose to faction change and decide that they regret the move. If a player has never played for an extended period of time on the other side they may be unhappy with what they find there. This could lead to lack of interest in playing,playing, poor performance, and eventually the player could stop playing all together. Or at least until they are eligible for faction change again.Thankfully after looking at the data at wow gold Census it appears that the faction changes have had little to no affect on Horde and Alliance population. As always they are fairly even, with Alliance slightly ahead. I will admit when I first heard the news the first thing to go through my head was "Oh great just what we need a billion more Night Elves named Legolas or some variation of it.". No offense intended to any Night Elf.This does not appear to be (thankfully) the case at all. It appears those jumping ship so to speak are those who are very certain about their decision and do not take the choice lightly. This means that very few people overall are actually using the faction change option so far, making the population of both Horde and Alliance remain relatively normal.