I'd say they turned out pretty good. The first thing Jason said when he tasted one was, "it tastes like ice cream!" And they really do taste a bit like ice cream - ice cream with blueberries and chunks of nectarine mixed in.
I didn't have enough popsicle molds to freeze all of the mixture at once, so I stored the mixture in the fridge and made up new popsicles whenever we ate some. Then Jason decided he didn't really like the whole blueberries, so I added the rest of the mixture to my Ninja with a ripe banana and mixed that up really well - and we had some very purple popsicles to enjoy too. The banana added a bit of sweetness, because I really didn't add much sugar to the original mix - just enough to draw a bit of juice from the nectarine - and let the sweetness of the Nutchello be enough. Both options were really good.
I'm not sure why I never thought to use sour cream for popsicles before, but I am ready for some other versions now, like maybe these Strawberry and Sour Cream Popsicles. Mmmm, so many possibilities, and they're such a fun treat on a hot summer day.