What is the status of the CiviCRM rules extension? I have read a few blog entries but not sure when it will be ready.
From what I have read, it is supposed to work much like the Drupal rules module but works from within CiviCRM
Big part of the "engine" of CiviRules is finished, with the rest being completed this month already. As with many other open source development, the rest is depending on funding.
The extension then needs to be populated with specific events, conditions and actions, just like Drupal Rules. We then hope many more will participate in adding those. @ErikH is the one to talk with.
(CiviRules should not be confused with the CiviCRM Rules extension, which simply syncronizes CiviCRM with Drupal Rules. This is the extension Eileen is referring to: https://www.drupal.org/project/civicrm_entity)
There is an inbuilt rules extension - which exposes some drupal rules (through the Drupal rules UI). You can enable that and it does work.
However, it is more common to use the civicrm_entity module - https://www.drupal.org/project/civicrm_entity - (use the 2.x-dev version) which exposes CiviCRM entities as if they are drupal entities, allowing crud actions through Drupal Rules.
Also note that the CiviCRM entity module allows you to use entity reference fields - ie. to link drupal entities to CiviCRM entities. Depending on your use case entity reference fields can obviate the use for rules (e.g if you are going to use rules to replicate the data on both entities for the purpose of views the linkage will allow you to display both entities in views without duplicating the data.
The CiviRules extension is not yet stable enough for common use. What we have developed so far is a framework for the rules. This framework is ready but what is missing are what we call Events (which is a trigger to a rule), conditions and actions.
As Flying explained to get more conditions and actions we need more funding to complete those. If you don't have funding but you need some conditions and actions which arent implemented you are more than welcome to implement those.
There is a wiki explaining on how you could do this. See http://redmine.civicoop.org/projects/civirules/wiki
If you want to try out the CiviRules you could see a demo at https://civirules.edeveloper.nl and the source code of the module is at https://github.com/CiviCooP/org.civicoop.civirules
At this moment the CiviRules extension has been developed and tested with CiviCRM versionb 4.4.x, which is the LTS version.