Dole whip is essentially cold soft-serve pineapple whip served in a cup. You can also get a Dole whip float which is the whip served in a cup of pineapple juice (yum!!). What makes the Dole whips at the parks so special is that they use Hawaiian grown pineapples which taste a lot more buttery & generally better than the general-use pineapples that Dole grows in South America and ships to supermarkets.
I cannot tell you how good it is because there is alway a 20+ minute wait line. I'm just kidding. But they are so good. They are adding new Dole drinks over at the new Fantasy Faire with Maurices Treats. I will be sure to try one in a one month