This article states that ATT has reversed its position about VOIP over 3g. When combined with ATT's international buckets of data, this could be an attractive option for many international travellers. The trick will be trying to stay within their buckets of international data:
Truphone says that a ten minute call over SIP using AMR codec takes about 1 meg of data. I'm not sure what rule of thumb we can give people, but it will add some interesting possibilities. This summer I used VOIP over 3g in Sweden (using a local prepaid SIM) and the calls worked pretty good. It was mostly an experiment since I had 15 euros to burn on my last, but I was impressed. I wouldn't do a business deal over it, but it was fine for friends and family.
There was never a opposition to VOIP from AT&T if you ever read the ToS it specifically states "authorized" VOIP. A lot of companies never bother to ask and just do or never tried to work out a deal. So they are unauthorized.
I would presume that most users are individuals. VOIP over 3g isn't up to business standards. As I've noted before, I did VOIP over 3g from Europe but I ran echo tests before I made the call and certainly knew not to try and make calls on EDGE, on moving trains, etc. Tell that to a sales rep.
Blackberry's new mobility solutions will be the first step at attempting to send corporate voip out to users, but I'm pretty sure that it will still carry the voice over a voice channel but move the caller-id, dialing requests, and service codes to data. I have not exhaustively reviewed the issue. I suppose however that you raise a good point. ATT has authorized Skype. It hasn't technically authorized other carriers, but as long as they move their stuff to iLBC, G729 or another efficient codec, I presume that ATT will authorize it. A system like Blackberry which made mobile phones effectively remote handsets on a corporate PBX system would have a fair amount of appeal and I suspect that ATT (or its competitors) could find a formula that monetized it. I work in law and I've often had to pull CDRs to reconstruct telephone time lines. I can pull my own CDRs without permission. I'd love to pull my mobile numbers at the same time and I'd love an easy way to push my office caller id when calling clients. (I can do it now by calling our voicemail backdoor, logging in with a PIN, and calling out, but it is a pain).
iPhone users will have one unique rub which is that the VOIP program pretty much has to stay in the foreground to work.
I agree with you. I figured eventually everything will go over digital in the near future, and there will no long be a voice plan. You will get a chunk of data that'll cover X minutes per KB and once you run out you'd probably pay $2 per MB and if you had a data plan it would not take your pool of data used for voice. I believe Planted-Ed and a few other people have also mentioned this. As technology progresses this is what we see.