I bought the Garmin 1000 bundle with the intentions of using the speed & cadence sensors with my Garmin 800 on my mountain bike (using it to commute to work right now).
It took a while to figure out, but the Garmin 800 will ONLY allow one wireless device to be attached in the speed/cadence section. So I can set the device type to cadence, it will see the wireless cadence sensor. And if I set the device type to speed, it will see the speed sensor.
Spending an extra $100 for the bundle is certainly not worth it if I can't use both wireless devices. Granted, if I only use my Edge 1000, it sees both devices just fine but for commuting on a daily basis, I won't do this.
Since Garmin lists the wireless speed and cadence sensor bundle as being compatible with the Edge 800, I hope they are fixing this!
https://buy.garmin.com/en-US/US/shop-by-accessories/fitness-sensors/bike-speed-sensor-and-cadence-sensor/prod146897_010-12104-00.html