MostlyWater, the idea of an upside down cake is to DELIBERATELY put the fruit on the bottom of the pan, before you pour in the batter. So when it's cooked, and you flip it upside down, it presents with the fruit now on top.
If you didn't flip it, if you left it in the pan to cut it, all you would see is the top of a yellow cake. True, the fruit would be on the bottom. Then you call it a Blueberry Surprise Cake. LOL!
Here's a pic of a blueberry upside down cake. http://chowtimes.com/photos/2007/02/...4_edited-1.jpg
Pretty, isn't it?