I hadn't heard anything about it til this last week; then again, I've been out of the country for two weeks. I did read a brief article that said the members (so far) are overwhelmingly male (while FB is about 50/50 male/female) and has a high % of techie types.

I'm passing for now. Heck, I just signed up for FB this spring. I can't handle yet another new social media thing to keep up with.