Creative says the Wireless Rock Speaker is a "high-quality stereo speaker encased in a granite-rock like exterior," and is designed to "withstand moderate weather conditions so it doesn't have to be brought in every time it rains." In other words, the speaker isn't entirely weather-proof but it seems to be water resistant.
Alas, the Wireless Rock is not a Bluetooth speaker but works with the $100 Sound Blaster Wireless USB audio system, which is available separately (bummer). Once you plug the USB accessory into your computer, you can then stream music wirelessly from iTunes, Pandora or other music apps (your computer must be 100 feet away from the speaker).
Source: CNET