At a 4 drop and only 2 loyalty she seems to me to be one of those types of cards that depending on the situation can be useless or completely awesome (wait a second, that's like most cards in this game).
The major reason people use the non-ultimate -X ability right after they land the Planeswalker right now is because of the potential of Hero's Downfall or lethal attacker damage on the board already. It really depends on what your opponent is playing. As primarily a Standard player who only so far dabbles in EDH I can see how differently people who focus on different formats might look at this card.
Most board wipes in EDH deal with creatures, letting this survive with a big creature later in the game potential still growing. Meanwhile her +1 ability let's you tag the biggest flying or unblockable creature on the board or some other damage inducing threat, this is generally a good thing in EDH especially if you consider the political side, your Planeswalker is stalling the guy who managed to cheat out the 7/7 flying trampler from abusing us.
In Standard it gets a bit more complicated. Especially not knowing what new cards are coming with it. Perhaps a Simic Permission/Control deck could evolve to push her to highly desirable. Her +1 is a better counter to a Desecration Demon than sac'ing creatures or tokens for 2 reasons 1) You don't need to sac something preventing it from growing 2) His demon is only a chump block if you attack with smaller dudes.
I think there is potential, but I don't have a major boner for the card in general, that might change after we see some more spoilers.