I've already concluded in my mind that I'm not going to try to do the whole "Grievous is Maul" subplot. It's way too much work for something that I don't think pays off ultimately. The story is supposed to be about Anakin, after all. Not Maul and Obi-Wan.
However, I do have plans to alter the Grievous character into somebody more compelling. Somebody who you actually can care about, and not just a random excuse to show off CGI.