I predicted Wii would be a massive success before it launched. My prediction then was based on the virtual console not the Remote but I was excited for the remote initially and could dig up old posts if I wanted to but not today.
I also predicted that Super Mario 3D World was the best game ever and needed a sequel and Captain Toad came along one year later.
But that is about it. I don't think I make very good predictions on features but I can usually predict with very damn good accuracy how the fanbase will react but that is a different story.