Personally, I like the new Fairy type.
After lots of rumors in various places, I'm not that much surprised about the announcement, but man I was excited when I read it.
Maybe the franchise didn't really need a new type, but when they know have decided to bring a new one, then Fairy is pretty original I think. A Light type, which also were rumored, would on the other hand be quite unoriginal, since that type already exist in other franchises (Like Yu-Gi-Oh).
The Fairy type also seems to be able to have it's own unique characteristics which I also think is important for a type. I think it will fit well into the current system, giving Dragon a total amount of 3 weaknesses, which is very positive for me, since you now have more options to counter them, which perhaps can slow down their dominance a bit.
A lot of Pokemon fans is probably dissapointed about giving some of the older Pokemon this new Fairy type, but I actually think that this is a positive thing, since these Pokemon can gain new interest in people instead of just being forgotten in the big amount of different Pokemon. Also, I think it is cool that old Pokemon are getting new significant opportunities in battle.
As rumored, these Fairy types will be weak against Poison and Steel, which I hope is true, since Poison currently only hits Grass types super effectively, so I think it could make offensive Poison moves more popular.