Ninfia is pretty, but definitely baffling as to it's type. Normal and Flying are the best guesses so far, but you'd think that if it were Flying, it would definitely have something more substantial to it's design other than just ribbons. But, then again, Shaymin doesn't look like it should be able to fly in Sky Forme, but it can.
I suppose a new evolved Normal eeveelution would be interesting. I just wonder if it would make Eevee itself a little redundant, beyond having it for evolving into other eeveelutions.
And who knows, it may be something special that has multiple types.