I wouldn't count on that third book ever happening. It was first announced in 2005, the same year as his death, and I believe Amazon has had a page for it (with cover art) since at least 2006.
Good to hear this! I've had volume 1 sitting by my bed for a few months now but still haven't cracked it open. I'm not really sure why... length, maybe? This might be what I need to start