not sure how much they CAN follow the books now, though. They've already burned so many plot points that ended up being major themes in later books. Rahl as his father (and also his evil half brother) doesn't work as well if Darken Rahl is his brother, as it makes the new brother "just another evil half brother".
The plague storyline was taken from the same book and used for an episode here.
Sisters of Light, major players in the series, have already been pretty much burned up in a one-off reference. They're no longer from the Old World, no experience with Jajang, and seem pretty unlikely to be kidnapping Richard in the near future. The Sisters of Dark also were supposed to come out of that.
We've already played the "multiple copies of the Book of Counted Shadows" game. Suppose it doesn't really matter, though, as the whole point was to get the Boxes of Orden (again), and they appear to have been destroyed by Darken Rahl's bad luck.
Which also took away a couple other big points: Richard hasn't figured out how to be with Kahlan yet. Looked like they were going to include that as part of the finale, but they just dropped it out again, staying with the status quo. Suppose this way, they can keep them together rather than constantly kidnapping Richard or Kahlan to prevent them from being together.
Richard also never defeated Rahl, or really did much of anything to help his growth as a character (and leader). Instead of seeking the truth of the matter, and tricking Rahl, Rahl just died by accident. Fun. Actually, when you look at the entire final sequence, you really can't say that this season was much based upon Wizard's First Rule at all. The First Rule never even played into the defeat, instead of being THE reason for the defeat.
Again, it's an entertaining Fantasy series, and I like watching it, but they've really butchered it to the point where it's fairly dishonest to call it part of the Sword of Truth series. A few tidbits are tossed out here and there, names and locations, but most of the key components have been changed or tossed out entirely. With such a HUGE series to play with, and books with 10s of thousands of pages to draw from, it's a shame.
We haven't had this show yet - has Richard started murdering unarmed civilians or giving lectures about how torture is OK if it's done by good people yet?