You might find the genius lists go some of the way toward solving this problem for you. They try show things you're likely to be interested in, and don't show stuff you already own.
If my girlfriend wants an app that she's heard about, I've got to install it for her. Guess who updates the apps on her phone? :-(
It's gotta be real easy for most people.
I think you're failing to grasp that many normal people don't really want to go that deep with technology. People really do want simple.