For the first 300 pages or so, I kept thinking "What a freakin' delight." (That's about as high as I am able to raise the brow of literary criticism---I wasn't a very good English major.) I kind of knew some of the key plot points, but it still managed to surprise me with its crackling dialogue and a heroine both fiery and sensible, virtuous not because she's insipid but because she's whip-smart enough to foresee the consequences of her actions. Now to watch the film version with Ciaran Hinds(!).
ETA (May 2011): Ugh, that was a bad adaptation. Bad Jane. I guess we'll try the 2006 Masterpiece Theatre version next.
ETA (July 2012): Okay, I've watched five of these so far, and the only one I can recommend is the 2006 Masterpiece Theatre adaptation. I've got three more to go on Netflix, though...