The new Fictionwise code is 093011, and it gets you 25% off. (This is one of the lower discounts they offer, which is probably just as well since I've been spending too much there lately
.)
If previous experience holds, this should last until Wednesday night or Thursday, and will be layered on top of their normal 15% discount for new ebook releases (issued on Mondays - see the 'new ebooks' link at the top of their web page).