It's the Alpaca Silk. So I suppose it's worsted...

Hmmm... That might work... Hehe, I should know better than to post a knitting problem to you! :-P

I was also thinking, I have some kind of crazy unmarked yarn that might be fun to work into the pattern (picture coming, please hold)... So now I dunno if I should really cast on for these until I've got some sort of set idea as to which yarns I will and won't incorporate.