Lars,
I'd like build class similar to LuceneDatabase but using ElasticSearch instead. As you might already know, ES is built on top of Lucene and doesn't require any previous knowledge to begin using it. As it's more a Lucene wrapper, I've found that (almost) every Lucene setup can also be mapped to ES, so I believe it would be great to create this extension would also allow to scale up Duke's scope (I mean, you're not limited to a single machine).
I know you are (or will be) working on a new version of Duke. I don't know how much it will change so I ask you whether you believe it's a good idea to wait until the new version is released or I'd better start coding now.
Also, if you have any recommendation I'd be glad to read it.
- Antonio