Well, Bluetooth hasn't taken off due to the fact that the technology is still quite new, and also quite expensive. In addition to this, you may have heard security issues in mobile fones where the phone book can be accessed by someone without the owner even knowing.
I personally use Bluetooth on all of my PCs for the keyboard and mouse. Personally, I prefer it over radio wireless because of its shorter range (about 10-20ft) and higher throughput. But, with time, bluetooth may catch on since it does provide a good shortrange, low power, solution to traditional radio wireless.