Kiki's Delivery Service, Princess Mononoke and The Wind Rises aren't just arguably the best Studio Ghibli films, they are three of the best animated films ever made. Full stop. The lack of high-definition releases has long been figuratively criminal, and tomorrow all three films will finally see a release on Blu-ray from Disney.
You can watch the films in English or the original Japanese with English subtitles, and there seems to be a pretty decent array of special features on the discs. Here's the list for Kiki's Delivery Service, my personal favorite:
Introduction by John Lasseter
Original Japanese Storyboards
Original Japanese Trailers
"Ursula's Painting" - A musical montage of "Ursula's Painting". The painting was created by junior high school students and used by Director Miyazaki for the film
"Behind the Microphone" - English voice cast members Kirsten Dunst, Janeane Garofalo and Phil Hartman give voice to their on-screen characters
"Creating 'Kiki's Delivery Service'" - Director Miyazaki discusses how he created the world of the movie
"Kiki & Jiji" - Producer Toshio Suzuki reveals how Director Miyazaki based the character of Kiki on Suzuki's teenage daughter
"Flying with Kiki & Beyond" - The director discusses how he approached Kiki flying
"Producer's Perspective: Collaborating with Miyazak" - The producer talks about how he works with the director through the years
"The Locations of Kiki" - The real world locations that influenced the look of the film are revealed
"Scoring Miyazaki" - Composer Joe Hisaishi talks about his approach in writing the music.