The names of Eveelutions: Vaporeon - Showers - water type Jolteon - Thunders - electric type Flareon - Booster - fire type Espeon - Eifie (kinda like ESP) - psychic type Umbreon - Blacky - dark type Leafeon - Leafia - grass type Glaceon - Glacia - ice type Sylveon - Ninfia - ??? type From what I've seen of the other evolution's the names are meant to represent their types which means Sylveon is "MOST LIKELY" going to be a flying type JUST on the name alone no guarantees because this is GF were talking about here but it seems to be the most likely case. --- See you Space Cowboy.
I honestly cannot see a way it can be anything but normal, and that. IMHO, is a good thing. Normal types are awesome, especially with Eevee already learning powerful moves like last resort and trump card.
Admittedly, the flying-type advocates have a good argument, but Sylveon just doesn't look like a flying type. It doesn't have wings or a beak, and doesn't look capable of generating powerful winds. Its choices in flying-type moves are very limited.
Hoppip and its evolution don't have wings or beaks but they're still flying types. Also, we don't know what kind of new flying types moves will be introduce this gen. --- Whoopee damn do da.