It's been almost a month since the 7.x-3.0-alpha3 release, and a lot of work has happened since then.
1) Fixed several alpha3 regressions. Alpha3 accidentally removed support for advanced actions (actions added through the Actions UI). Now back (in actions_permissions as well). Also, global actions ('type' => 'system') weren't showing up, that's also fixed.
2) Refactored operation types, now implemented as ctools plugins. Operations are now objects, and contain all relevant logic. This allowed the main VBO code to be simplified a lot, leading to more maintainable code.
3) Reworked the Batch API code, resulting in much improved performance.
4) Reworked the admin UI (VBO field settings):
- Now possible to override the label of each operation (ported from 6.x-1.x)
- Automatically chooses the correct execution type based on the number of selected items (see README for more information)
- The drupal queue setting is now per operation, allowing only specific operations to be enqueued, which is more flexible and reflects better the intended use case.
5) Improved the rules integration:
- The config form now has access to all tokens for the current entity type (so you can use [node:author], or whatever you need)
- Now supports rules components that accept a list entity type (such as list<entity>, list<node>, etc) as the first parameter. Note that this turns on aggregation.
- Provided an action to allow Rules to load all entities in a VBO view (as a replacement for the "Execute VBO' action), as well as a condition that checks the number of results in a VBO view.
6) Many smaller improvements, including better default views, more documentation in the README, and bugs & notices fixed.