While im sad to see Pal Mickey stop at WDW, I hope this will lead onto the next generation.
I'm sure this was a cash cow for Disney, sell a very cute, high quality, interactive plush.
The infrastructure is still in place for this, so it would be to hard for them to reuse the emitters for a new system.
As for the iphone system its not that hard for Disney to privately provide the WDW application themselves. There are a number of ways to do it (and maybe offer the service to other platforms also).
the easiest way would be to provide the application over wifi. They could place general instructions on the park map, i.e. if you have the following device's:- iphone, win mobile, DS, PSP etc, activate your wifi and connect to network *mobile-magic* (or some-other magic, wishes, dreams, wifi network name). From there, you connect to a private website which has a screen with options for you to download the required software to your device.
Apple have the facility to allow private distribution of an application, they also have the ability to push information to your iphone over a wifi network (look up the iPhone Starbucks iTunes mobile store feature). So this isn't as hard as you may think.
Once the app is on your device use of either gps, cellnet location, or wifi location could be used to identify where you are in the park as seen on the DS device.
They could also use times boards to provide further instructions on how to download the application, like the way Disneyland Paris gives out bluetooth times at time boards, plus as there are usually cast posted nearby, so guests who are unsure can then ask a cast member for more info.
There are a million ways this technology could go, they could even post market research surveys onto the system, aimed at different ages, so if your kids are using, disney could ask which ride they like best, which characters they enjoyed meetings etc.
There's nothing stopping Disney from even making there own handheld device, that could maybe work as a MP3/movie player (backed up with a online store for extra revenue when guests leave the parks, allowing downloading of Disney games, music and short cartoons etc), that has extra features when used at Disney parks worldwide.
I guess all I'm saying is, I hope this isn't the end of the road of the interactive guide initiative, I love technology, and think there are a million possible ways that Disney could bring new experiences to consumer devices.