There are certainly phones being sold without forcing voice plans down your throats.
Blackberries are one example.
And why couldn't I use the iPhone sans voice? Email, web browsing, YouTube, movies, SMS, Google Maps, pictures, syncing with your Mac seamlessly... etc. I don't plan to use it as a modem. I plan to use it as a communications device. I just can't use voice (being deaf and all).
Frankly, I could go as far as calling this discrimination...
while i now understand why you don't need voice, i dont' think you can call it discrimination. AT&T is not keeping you from using the device with a voice plan. you just don't want to pay for the part you can't use. big difference.