WAP has been rolled out worldwide and is most successful in the U.S. and Japan. Content written for one WAP browser typically does not run well on another WAP browser. The same is true between all WAP browsers. Wireless models tends to be hierarchical, while PC Internet use works well in its current linear model.
Interaction is still mixed into content and presentation.
The standards must allow for the development of a single application for all wireless devices. Most wireless devices cannot be upgraded by consumers. Consumers will buy whatever device is popular. It will likely take 1 year for a new standard to solve this issue and for new devices to emerge using the standard. This means there will be 100's of millions devices with incompatible interaction models before a standard can be deployed with a solution.