In2Games has just announced a series of gaming peripherals even more amazing than the Wiimote - called the Fusion. The Fusion units work much like the Wiimote, sensing motion and depth. But because the Fusion uses sound waves (sonar?) for tracking movement, there are no issues with the remote losing line of site with the console. During playtests, the Fusion proved to be more than In2Games hype.
The Fusion will connect via USB and will run $56 bucks a pop...so those specialty remotes will start to add up fast unless you want to play golf with your tennis gear. Unfortunately, the Fusion is late on the scene and will doubtfully be utilized to its fullest potential - this gen at least.