MurmurHash version 3 was finalized on June 3. It provides an enormous speedup and increased robustness over version 2, which is implemented in Cassandra. Information here:
The reference implementation is here:
I have already done the work to port the (public domain) reference implementation to Java in the MurmurHash class and updated the BloomFilter class to use the new implementation:
Apart from the faster hash time, the new version only requires one call to hash() rather than 2, since it returns 128 bits of hash instead of 64.