You know the special type have one less type than physical type? Before the Gen 4, there are 8 physical types and 7 special types. So if the Light is made, it is most likely go in the special group. Therefore, we may have Dragon and Light evolution for Eevee. In additional, we may have our first full evolution Dragon-type Eevee.
I reiterate my belief that the fact that all Eeveelutions are formerly-Special types is naught but coincidence, and that I consider a Dragon Eeveelution to be rather unlikely, compared with, say, Rock or Poison.
I also say that GameFREAK has decided that a Flying mono-type isn't going to happen aside from moves and abilities that change your type, and though I don't get why, that's just what they've done, so I consider a pure Flying Eeveelution to be similarly unlikely. (Normal/Flying... possible. I still say Rock and Poison would be my choices, but I lean against ruling that one out completely.)
Creator of Jay's Journey (see quote!) "Game Series 1 is the best because it set the stage for better games!" - Nostalgia whores everywhere