I suppose it's all but exited theaters but I did see the 3-D version of The Lion King, in parallel to bunny_hugger seeing it, and had some thoughts to share. I'm incidentally glad the movie did return to theaters; it used to be part of The Way Things Are that Disney would re-release one of its classic animated pictures as counterpoint to grinding out, say, The Fox And The Hound, and while nearly everything may be available nearly all the time these days, it isn't the same. Even if Disney does put some cartoons ``in the vault'' before selling the newest videotape/DVD/Blu-Ray edition. (Do they? I remember it producing still funny arguments online, as all arguments online are funny.)
The thing about the 3-D conversion, here, is that it seems well-meant. It just doesn't work, not consistently. Some scenes adapt very well, particularly ones that try to show the awesome space of the Pridelands. If this 3-D craze established anything it's that the real power of 3-D in movies is not thrusting things out at the screen but letting space recede into infinity, and with scenes that were meant to convey immense distance the treatment is good.
What doesn't work are figures, particularly characters moving swiftly. Often, if characters are static, the treatments of shadows and lines lets the characters seem to have some natural bulk, although Mufasa and Adult Simba's eyes still looked like divots gouged into steel. But when a character moves, particularly moves fast as Timon often does, the distortion of the figure --- which looks so natural in the 2-D rendering --- means the shapes fall apart into their component bulges.
I think that's a fault of trying to paste 3-D effects on what were designed as 2-D figures, and that had the movie been designed from the start with 3-D in mind the animation would have fit better. (In support of this, there's a scene with Timon, Pumbaa, and Nala talking, and Timon elbows Pumbaa. In 2-D the scene reads perfectly; in 3-D, the characters are at different distances from the camera, and Timon nudges the space in front of Pumbaa instead.) And I'd like to see the experiment done, if anyone still bothers with hand-drawn animation, and if anyone still bothers with 3-D movies until the next time the fad goes around.
Trivia: The multi-plane camera Walt Disney studios constructed, and first used for the 1937 short The Old Mill, cost $70,000 to build and stood fourteen feet high. Source: Of Mice And Magic: A History Of American Animated Cartoons, Leonard Maltin.
Currently Reading: Come On Down: Behind The Big Doors At The Price Is Right, Stan Blits, with an introduction to make it look like the whole book might be by Bob Barker.
PS: Also, What's Remarkable About Naming Sixty?, which doesn't quite get answered. Should have an answer shortly, though.