There is now a new client, Astyanax, released by Netflix in January 2012.
"Astyanax is a Java Cassandra client. It borrows many concepts from
Hector but diverges in the connection pool implementation as well as
the client API. One of the main design considerations was to provide a
clean abstraction between the connection pool and Cassandra API so
that each may be customized and improved separately. Astyanax provides
a fluent style API which guides the caller to narrow the query from
key to column as well as providing queries for more complex use cases
that we have encountered. The operational benefits of Astyanax over
Hector include lower latency, reduced latency variance, and better
error handling."
The source code for Astyanax is hosted at Github: https://github.com/Netflix/astyanax
