Just figured it out... Umbreon * and Espeon * will NOT be in the set. How do I know? Weeeeeell...
It's confirmed that Jolteon * is #101 in a set with 108 cards. There will also be 6 holo energies in the set. These come after the *s, as proved by HP. There are also confirmed to be 8 exs in the set. Absol ex is #92, and is obviously the 1st ex. (the only Pokemon that comes before Absol alphabetically is Abra) So, we know that the bottom of the set will look like:
92: Absol ex
93:ex
94: ex
95: Metagross ex
96: ex
97: ex
98: ex
99: ex
100: Flareon *
101: Jolteon *
102: Vaporeon *
103:Fighting Energy
104: Fire Energy
105: Grass Energy
106: Lightning Energy
107: Psychic Energy
108: Water Energy
This is probably nothign new, since there have always been only 3 *s at most. But it's a shame they're not willing to put in an extra 2 *s.... which we will now never get.