According to this post by Google, they are no longer going to actively develop Jaiku and will release the engine as an open-source project.
As we mentioned last April, we are in the process of porting Jaiku over to Google App Engine. After the migration is complete, we will release the new open source Jaiku Engine project on Google Code under the Apache License. While Google will no longer actively develop the Jaiku codebase, the service itself will live on thanks to a dedicated and passionate volunteer team of Googlers.
Well, I guess it could be worse. I still like Jaiku. Hopefully, this won’t affect TwitKu.com