Voice is rapidly becoming another channel to plug into the Internet. Voice input may be from your computer, a telephone or a kiosk. The combination of voice and wireless devices is making the Internet truly mobile. WAP plays a significant role here. Speech recognition, both client based and host based, is getting better and better.
Powerful hardware enables the speech recognition servers to scale.
Text to speech is sounding almost human and less mechanical. Broadband wireless is upon us. It will happen. All the ingredients are there. It is a matter of some skillful engineering to knit these together.