Yii Activerecord

I was recently working on a project based on CodeIgnitor and found some of the ActiveRecord methods very useful and easy to use. For reference, here is the ActiveRecord API - http://codeigniter.com/user_guide/database/active_record.html

I was wondering are there any plans to implement some of these methods in to Yii, for example select_max(), select_avg() and where_in().

Also is there likely to be any support for sub queries?