The Couchbase .NET SDK version 2.2.2 has been released, featuring bug fixes and improvements for future enhancements to the IO engine and deserialization options. The release addresses several issues, including incorrect retry logic, serialization problems with certain data types, and performance improvements. Additionally, new features have been added, such as support for more deserialization controls via ITypeSerializers, making it easier to customize the SDK's behavior for specific use cases.