The new release of the MongoDB Connector for Apache Kafka version 1.4 offers several key features, including Selective Replication in MongoDB, which enables tracking of just the data that has changed by using Change Data Capture (CDC) events sourced from MongoDB, allowing for a lightweight way to perform basic replication of MongoDB data via Kafka. Additionally, Dynamic Namespace Mapping and Dynamic Topic Mapping have been added, enabling users to dynamically map namespaces to collections and topics based on specific field values or business logic, providing more flexibility in data integration and processing.