I don't think it is waterproof in the sense that it can be submerged. But then I personally don't need a LRF that has that ability! Since mine is so new, I haven't tried it out in all weather conditions yet. However, I did have it out in some pretty heavy rain about a month ago, and no problems occured.
I kind of doubt that Leica would let one of their products out on the market if it didn't have what it takes to handle heavy rain etc. since that would be so damaging to the Leica brand name.