Castle is one of my favorite LEGO themes. The monster/fantasy focus in the newest incarnation has been a lot of fun. And, at the same time, the Medieval Market portrays a domestic side of things that has been long desired.
I'm looking forward especially, however, to the Elflands sets hinted at in March/April 2009 magazine.
Yes, I remember that small section of the magazine illustration causing much discussion on the old forum! I was wondering if anything new regarding this would be forthcoming at Toyfair but no sign of it yet.
If it's something that TLG are considering then it would be nice to see them go ahead with it - it could be good for the Castle line on two fronts: 1. it meets the criteria of being a new and different addition to the line and 2. the general theme of "elves" seems to be perenially popular and tends to provoke interest from a core group, whatever the franchise or product line it appears in. Elves are now a pretty universal theme in many Fantasy novels and games and certainly aren't restricted to any one intellectual property so hopefully TLG shouldn't have trouble with copyright/licensing if they wanted to go ahead with this.
Let's hope they do decide to follow up on the Elfland sub-theme, either later this year or next year.