While the basic idea of using PG logical decoding for CDC is the same, Debezium is a completely different code base than Bottled Water. Also we provide connectors for a variety of databases (MySQL, Postgres, MongoDB; Oracle and MongoDB connectors are in the workings). If you like, you can also use Debezium independently of Kafka by embedding it as a library into your own application, e.g. if you don't need to persist change events or want to connect it to other streaming solutions than Kafka.
In terms of CDC use cases, I keep seeing more and more the longer I work on it. Besides replication e.g. updates of full-text search indexes and caches, propagatating data between microservices, facilitating the extraction of microservices from monoliths (by streaming changes from writes to the old monoliths to new microservices), maintaining read models in CQRS architectures, life-updating UIs (by streaming data changes to Web Sockets clients) etc. I touch on a few in my Debezium talk (https://speakerdeck.com/gunnarmorling/data-streaming-for-mic...).
Any plans to support SQL Server? (SQL Server is prevalent in the enterprise world)
Debezium seems to be a production version of Martin Kleppmann's CDC-to-Kafka POC, Bottled Water [1].
Database replication is the killer app for CDC, but CDC can be used for so much more than replication, like event-based alerting, triggering, etc.
[1] https://www.confluent.io/blog/bottled-water-real-time-integr...