i did too and loved it.
was the mini-series stuff recent? becasue i'd browse the boards at IMDB quite a bit, and basically it sounded like it's done. The creator David Knopff basically sold the entire rights to HBO and it's their call as to what they want to do with it. he said he had about another 10 years of actual story that would need about 40+ episodes to tell, and said that he'd rather see it unfinished than have some weak mini-series wrap it up
i believe he was also interested in finishing it in book form, but alas, HBO has the rights
sorry i dont have any links, but the Carnivale board at IMDB has some decent info on it
i do know HBO is wrapping Deadwood as a mini-series though, so there could be some hope, but i'm not counting on it