I've only met one Julianne. She's a beautiful girl and a very talented ballet dancer. Other than that, I don't know what kind of person I might think of when hearing the name Julianne. I don't really like it as much as Juliana/Julianna. I like names that have the Juli- prefix, though.
My name is Julianne. I am 39 and I grew up constantly having to correct people on my name. I don't understand how it is so difficult to pronounce, but I often get Julianna or Julian. I love my name and can't stand it it when it's not said correctly. I remember thinking how cool it was, as a kid, seeing Julianne McNamara on the television during the Olympics for gymnastics.
I have to admit, this name endears itself more and more to me because of the stunning Julianne Moore. I love Julia, but I think Julianne is a gorgeous name as well.
This is a beautiful, elegant name, and it sounds a bit more mature than Julianna, although I like both. Not many names that are basically combinations of two names are good, and this is a nice exception to the rule. It's too ordinary and common for my taste, but very nice.