I think a very useful advance in heart rate monitors for sports would be getting rid of the chest strap altogether. I hate wearing those things. Can they develop sensors that are sensitive enough to monitor the heart rate at the wrist? Then the sensor could actually be in the watch itself. That I would like to see.
+1 on looking forward to advances in wearable medical and fitness sensors. I'm waiting for something more along the lines of the Scanadu Scout - claimed to be the first medical "Tricorder" - combined with the ability to monitor things like blood glucose levels and cholesterol etc.
I mentioned the FitBit pedometer in my comment on your other blog. It has become a permanent part of my attire. I am also looking forward to further advances in strapless heart rate monitors that can be worn during all waking hours -- but do they all have to use the wrist watch form factor? I have a traditional chest strap + wristwatch style HRM that I only wear when deliberately exercising, but even if I could jettison the strap, I wouldn't want to wear a watch all the time.
I also look forward to advances in another realm of body sensors -- namely, body and limb motion and force sensors for the casual athlete. Olympians and professional athletes have had access to lots of sensor-based motion analysis for many years, but this technology has not yet been productized for the masses.
I am reminded of a ski racing clinic I took many years ago that included video analysis by an instructor who pointed out everything that was correct and incorrect with each skier's form, posture and movement. The problem is, the video setup only captures a brief period of time and space (a few turns on a particular course) and is lacking in hard data. It occurred to me how amazing it would be to get real force and motion data -- arms, legs, torso & head -- for a full ski run with varied terrain, and then review that with an instructor. Better yet, with automated analysis and real-time feedback, such a system could be used as a type of biofeedback system, so you could make adjustments in real time based on objective measurements of what you're doing right and what you're doing wrong. This could be applicable to casual athletes in many different sports.