An issue which affects memcached bucket types, where it was found that the hashing was not compatible with Couchbase Server's proxy port (a.k.a. moxi) has been fixed in this release. It is also incompatible with the spymemcached 2.7.x compatibility with Couchbase (and Membase). Note that this means the use of the 1.0.2 client is INCOMPATIBLE with 1.0.1 and 1.0.0.
An issue which would prevent failover in some situations was fixed in this release. Prior to this fix, a permanent failure of the node the client was receiving configurations from (typically from the first node in the list) would cause the client to stick with an old configuration, and thus it would not know about any failovers or changes to cluster topology.