Creator Killer: Morgan's career after this has been exclusively in TV.
Executive Meddling: The original version of the remake had, among other things, more character development and deaths more akin to the original; Dimension Films stepped in and started demanding rewrites and re-shoots (they're infamous for this sort of thing, see Halloween: The Curse of Michael Myers and Hellraiser: Bloodline) to the point that director Glen Morgan has gone on record to say he hated the movie.
In Memoriam: The words "Goodbye Shirley" can be seen early on in the credits in honor of composer Shirley Walker. This was the last film she worked on before her passing.
Meaningful Release Date: The remake opened in the US on December 25, 2006. The UK got it ten days earlier, on December 15th.
Missing Trailer Scene: Due to Executive Meddling, the trailers were loaded with footage shot specifically for promotional purposes because the producers didn't think the film itself was marketable enough. This didn't sit well with the director.
Originally, the big twist was that Billy had died at the asylum and it was Agnes doing all the murders. Agnes was only his half-sister, not his sister/daughter; Leigh was supposed to live at the end; and the movie was supposed to end in a similar manner to the original with Leigh and Kelli getting a phone call from Kyle's cell.
This specific ending was actually filmed but eventually discarded in favor of the current one.
Glen Morgan wanted Andrea Martin or Margot Kidder, who played Ensemble Darkhorse Barb from the original, to play the house mother. The house mother in the remake's first name is Barbara, an obvious homage to Kidder's character, despite Martin playing the role.