Volume Three is chugging away nicely over on Alec's Blog. 3.11 has just been posted and there should be a few more updates during Feb.
Volume Three could turn out to be longer than the previous two but there will be a release of the completed Volume in various formats for download once Alec hits a pause for thought in his current run of tribulations.
Volume Four - currently in rough outline with partial first draft will be the final instalment. I have no idea what I'll do with myself afterwards O_O