Where a ghost once appeared in your Doombuggy, you'll now have a much more interactive experience. You'll notice that in one instance, the ghost takes off his beard and puts it on a guest and as the guest moves his head around, the illusion of the beard stays on his face. Disney is using some pretty major motion tracking technology. (Makes me want to watch Jurassic Park again...spare no expense.)
Watch the video below from www.InsidetheMagic.net
I can't help but think of author Cory Doctorow's book, "Down and Out in the Magic Kingdom". The story is set in a distant Utopian future where a battle is waged over the wiping out of traditional Disney rides in favor of just having the experience of the ride flash-baked into your brain. (Kind of like "the box" from Batman Forever. Yeah...I just referenced Batman Forever.)
While I usually enjoy ride updates, I admit that it does make me a little squeamish seeing The Haunted Mansion messed with, though the original still stands at Disneyland.