I think that the Eeveelutions are finally making a comeback. For people that play in the Unlimited format, such as me, (assuming that this is the format in which any card from all sets ever made is fair game) the new Eeveelutions will combo quite nicely with the UF Eevee. One energy for 30 damage (20 in Jolteon's case) with bonuses instead of drawbacks is an excellent game-opener. The Eeveelution-ex cards will likely see less play due to these new Eeveelutions. Then there's Leafeon Lv X and Glaceon Lv X to consider on top of all of that. Leafeon does a minimum of 50 damage for just two energies and gains additional power for each of your own energy cards and not just on Leafeon Lv X. Leafeon itself isn't a bad staller, either. Glaceon itself is also quite nice. Snow Cloak can especially make a nice and lucky opening move. Then there's its upgraded self, Glaceon Lv X. As mentioned before (and clearly read), it renders Poke-Powers useless, thus crippling any hope of using draw power with the PK Delcatty and Magneton. Metanite will destroy it, though. I'm somewhat dissappointed with the Leafeon Lv X and Glaceon Lv X card art... Especially with the normal Glaceon. I was hoping for much better art than that, but meh... Eeveelutions are still Eeveelutions! =D
Cresselia Lv X is way overhyped if you ask me. It will likely be spending most of its time sitting on the bench for its Power, and even that takes some time. Not a bad choice for healing, though. The power is basically a beefed up Shady Move (Cresselia Lv X's power doesn't require the user to be the active pokemon). Its attack is a bit conditional due to its low damage for a Lv X card. That's probably just me, though, since I hate using cards that are conditional unless it's an effective counter against an over-used card or combo. I'm not saying that it's a bad card or that its not worth using. I just think that people are blowing it way out of proportion, thinking it's one of the best cards in the game, because it's not. It's also quite vulnerable to Gust of Wind and any somewhat decent psychic-type, as the somewhat dissappointing HP stacked with a x2 psychic weakness doesn't help things. That's of course concerning the Unlimited format. In Modified, it will need to watch out for the Espeon also found in this set. Espeon is sure to appear in most Eeveelution decks for its +20 HP support, making Cresselia's job all the much harder (somewhat).
All in all, though, I think that the game, overall, is beginning to experience the next big boost in which will define what cards are good/ok/terrible, as the energy requirements are becoming less than they were in the Ex-series. That may be just me, though.
PS - Pardon the long post.
---EDIT NOTE---
That may be just me, though.
I tried lower-casing "may," but it won't let me. Everytime I edit it, it returns to its annoying capitalized self. D:< Oh well.