The future of WAP depends largely on whether consumers decide to use WAP devices to access the Web, and also on whether a new technology comes along that would require a different infrastructure than WAP.
On the consumer side, the factors largely involve the limitations of WAP and of handheld devices, the low bandwidth, the limited input ability, and the small screens all require users to adapt from their regular Web-browsing expectations.
In the next few years, mobile phones will start to benefit from very high bandwidth capabilities. The 2.5G/3G systems will allow much higher capacity and data rates, than can be offered by the restricted bandwidth currently available.
These wireless devices will be supported by a number of emerging technologies including GPRS, EDGE, HSCSD, and UMTS:
So what is the future for WAP? It has been designed to be independent of the underlying network technology. The original constraints WAP was designed for - intermittent coverage, small screens, low power consumption, wide scalability over bearers and devices, and one-handed operation - are still valid in 2.5G and 3G networks.
The bottom line is that WAP is not and can never be the Web on your mobile phone. WAP is great as long as developers understand that it's what's inside the applications that matters, and the perceived value of the content to the user. The browser interface itself, while important will always be secondary to the content.