Scroll down and read the message board comments. I found this one very interesting and discouraging.
From Coaterbuzz.com's SONiC Senshi:
The system on Pooh's Hunny Hunt at Tokyo Disneyland is very expensive and complicated. The technology can best be simplified as an "indoor GPS", which involves trasmiting data to the vehicles through titles on the attraction floor. This other system that WDI is looking into sounds like a much cheaper alternative that doesn't require Oriental Land Company's deep pockets. ^_^