No, ballet/acro was never an Olympic discipline, although it was a "demonstration" sport in Calgary '88 and Albertville '92.
It used to be a FIS World Cup and World Championship Freestyle event, however it slowly died off as athletes ceased to do the combined even and began to specialize.  FIS discontinued it entirely in 2000.
Some history relating to NS: some of Newschool skiing's pioneers were ballet (acro) skiers.  Toben Sutherland was a world cup ballet skier who was also the first skier to land doubles in quarterpipes.  (As a side note, I doubt that anyone who knows who Toben is would ever call him "gay").
 Jonny Mosely was a combined skier until 1996/97, he used to do his ballet run to "Ice Cream Man" by Van Halen.
Some of the guys were doing flatland 1080s as well as working on double poleflips (ie, the skier would flip twice, not the poles).
You could mention that ballet skiers were featured in a James Bond movie intro (can't remember which one).
Hope that helps a bit....