Though one has to question if it's enough. Isaac is apparently only "so so" popular in Japan and is neck and neck with K. Rool over here in the west. If his Japanese lukewarm reception is enough to damn him, things don't look so good for Shantae in my eyes.
Over in the K. Rool thread, we're currently speculating that Wolf will be the last returning veteran with up to 3 newcomers selected from the Ballot. Although it's not a guarantee, the Miiverse contests ending for Smash (Unity being the last one) signifies that Sakurai and co. are likely wrapping up their post launch content development. I'm willing to bet my bottom dollar that King K. Rool and Isaac will be 2 of those 3. It remains to be seen if Shantae can take that last spot, assuming such a spot exists. It's all conjecture right now but "4", including Wolf, seems to be the magic number right now. More than 2, but less than 6 (which I personally feel are the absolute minimum and absolute maximum respectively)
Edit: PITTY PAT IS NUMBER 1!?!?
PITTO IS UP THERE TOO!?
Dat Kid Icarus Uprising!
And Palutena and Viridi...and? Waaaa?
WAAA!?