It will be odd for all these Normal types to become Fairies. Going by the almighty Rumor, pure Fairies will be weak against Steel and Poison, and resist Fighting and Dragon. That would mean that Blissey's only current weakness, Fighting, would now be resisted by it. All of a sudden, after 6 generations.
By the way, another Normal type that will probably become a Fairy, besides the ones already mentioned in this topic, is Togepi, whose evolutions will probably be Fairy/Flying.
"The most important thing is to never stop questioning." -Albert Einstein. Xbox Live: AlteraLateralus