A few of the old indexes are online, for example C33, Chancery Orders and Decrees for Elizabeth's reign. I don't suppose there are plans to digitise more.
Most of the effort now is on WAALT, which has a search function. Just a rough guess, but I think most of the work has focused on the 16th and 17th centuries, for example Chancery (C78), and Star Chamber (STAC).
We have been indexing these records for almost ten years and less than 10% has been done.
http://www.uh.edu/waalt/index.php/Main_Page