I think there is one word that best describes this salad... YUM-O!! I love this salad! To me it tastes more like a dessert than a salad. I highly suggest if you decide to make this salad, you might want to double the recipe, because I found I couldn't stop eating it!
Wash grapes in a colander, remove stems, and pat grapes dry with paper toweling.
Place the grapes in a large bowl.
In a separate bowl stir together, the cream cheese and marshmallow creme, until it's smooth and creamy.
Using a large rubber spatula, (or a spoon) fold the creamy marshmallow mixture into the grapes, until the grapes are well coated.
Cover the salad, and place it in the refrigerator for an hour or two, before serving.
*Note: When making this salad, be sure you weigh the grapes after removing them from the stems, and before making the salad, to make sure you have exactly 2 lbs. Actually today when I made this salad, I added a bit more of the grapes (2-1/4 lbs.) total, as there was plenty of the marshmallow mixture to coat the grapes.
8/9/2012: Today when I made this salad, I only had 1-1/2 lbs. of grapes, and just 4 ounces of the marshmallow creme, so I just added 4 ounces of cream cheese, which I softened in my 900 watt microwave oven on power level 3 for 2 minutes, plus I added a 1/4 cup of sour cream, a 1/4 teaspoon of vanilla extract, and 1/2 a tablespoon of granulated sugar. Stir well to dissolve the sugar.