Interesting that you mention DSLs like Drools and Esper. One of the things we'd like to do is explore ways to bring the complex/composite event-processing (CEP) functionality to Kaskada. SQL does include "match recognize" at this point, but it is still pretty unwieldy to use.

With the shift towards general event-processing, we'd really like Kaskada to make it easy to express queries like "how many times do X happen within an hour after Y with these properties" -- the kinds of things that Drools and Esper provided!