Google Glass has serious privacy implications, which I hadn't considered before having them pointed out. I think there may be ways to get around that, but I'm not convinced Google cares yet.

I personally enjoyed PlayStation Home a great deal more than Second Life for virtual-world-style immersion, just because the UI is about a tenth as complicated and ten times more enjoyable. It's also designed around the assumption that you'll play games in it. I realize it's harder for indie developers to break into, though, and has no Free Software implementation.