So it's like Alfred workflows for Spotlight? This stands or falls with the plugins that will get developed by its users; one of which Alfred is thriving [1]
It's primarily an API on which developers can build plugins in Python (though doing a lot of useful stuff actually requires calling out to Applescript, of all things). There's no visual workflow-builder like in Alfred, although you _can_ set up triggers for Automator workflows.
Why are Flashlight plugins written in Python? (I'm asking out of curiosity; I like it.)
JS and Ruby are bundled with OS X as well and Apple started offering some JavaScript APIs in 10.10 for stuff that could previously only be done with AppleScript.
