There has been a new mailing list created for those who are working on Cassandra clients above thrift and/or avro. You can subscribe by sending an email to client-dev-subscr...@cassandra.apache.org or using the link at the bottom of http://cassandra.apache.org
The list is meant to give client authors a discussion forum as well as a place to interact with core cassandra developers about the roadmap and upcoming features. Thanks to Cliff Moon (@moonpolysoft) for starting a discussion about client quality at the Cassandra Summit.