AKB48. I'm not really a fan of the music, I just like the whole theatre concept. I'll probably tell some friends eventually. I've been exposing myself to a lot of things in the Japanese culture lately, so I doubt it would come at a surprise to them.
edit: talked to a few friends about it over the weekend after watching the SNL JPop skit.
I can't think of anything else right now. I'm very apathetic towards things like this, so I generally don't try to hide things that I enjoy.