We are adding features to the rules engine API and looking for developers who want to test these during an early access period. Sign up here:
Can we please know what the new features are?
Done already 
Several new enhancements to the API (Conditions). All you need to do is sign up for the developer preview. We will have a special section to talk about building rules for those in the preview and we will be adding more conditions/actions over time for developers. Full list of features being added will be available in the group.
A couple of you asked for “else” to be added to the rules API. It’s already in there.
Not at this time