Andy has some sort of disease that causes him to vomit violently for days when he has a attack.Last I heard he was gong to see a specialist in May.
The Historicon vendor list hasn't been posted yet so I'm not sure if he is coming. If he does turn up on the list I'd say its a good sign he is getting better.
Real shame as he is a great guy and used to be convention director for one of the cons.
I think he is a LAF member too so you might try PMing him.
Pete