In the developer preview for the 2.2.0 release of the Couchbase SDK, several enhancements have been introduced, including extended support for N1QL and Multi-Dimensional Scaling (MDS), improvements to Sync and Async APIs, and supportability enhancements through metrics. The N1QL DSL functionality has been expanded to include a wide variety of functions, while MDS now supports Memcached buckets more effectively. The APIs have been modified to ensure consistency, with "parameterized" queries being standardized across documentation. The transition from "hot" to "cold" observables aims to improve retry mechanisms, and new overloads in the synchronous API provide greater flexibility. Additionally, always-on latency and runtime metrics have been added to the SDK to aid in application monitoring, and various dependency upgrades have been implemented. The team is also working on extending the Kafka Connector and has made changes to the DCP in the core-io library, with further improvements and documentation planned as the release approaches general availability. Feedback from users is encouraged to refine these updates and ensure a successful full release.