This is great. I like the idea of an audit log. Especially being able to identity who deleted a page or content block. Who changed a configuration setting.
I would like to suggest that the log should be secure, even other admins can't go in and delete entries. One would need direct access to the data tables to do that.
The ability to pipe off the audit data to another storage source so even people with access to the data tables can't delete there actions. I don't want the audit to grow my database to a massive size either.
I would like to be able to raise my own audit events through the Event system.
I would like to be able to search the audit. Type in a key word and find all the references. Specify a user and track what they have done on the site. Really important that the audit data is accessible and presentable.
Levels of Auditing allowing me to do basic auditing to verbose like auditing.
I am not fussed at "what" can be audited on the first release as that can always be increased over time. But its the functionality of the audit and the ability to extend it that is the most important stuff on day one.