From my understanding, Dave is extremely ill..though I won't go into the details as he doesn't want them known. Whether he returns to the community (Let alone theming) is unknown...even by him at this point. I hope he does but, if he doesn't, the mark he left on this entire forum will always remain untouched by anyone else.
I'm sure others can follow his theme foot steps. I just hope he gets better. He is really a cool guy and has lots of patience with dealing with us addicts.