The way I see it the carriers see their business model being converted to an ISP dumb pipe one. Fact of the matter is not very likely. If I need phone services I won't rely on voip or skype or such like. I'll rely on a local carrier to provide this. So no their business model is not so endengeared but they should remodel a bit to offer better data services maybe offer some other things along the way(like music subscriptions and such that some are starting to offer). But it actually needs to be VALUE not ringtones and themes.

They also need to start treating their customers as more than just sheep. A year ago I found out that my 3g data only connection had blocked incoming ports while my regular line with a mobile data option had them all open. I contacted their service departemnt and they told no all are blocked(took me a while to get this message accross). I was hoping that the blocked stuff was a mistake but it appeared the open one was a mistake. I didn't really care so much for this but I wanted this inconsistency resolved. So I did ask them to fix the other link. I do wish they would offer a let's say 5eur/month extra so that you would be able to manage your own firewall and not rely on theirs(as in all incoming ports open).

I can't see this hapening but this is how they would make some extra profit for near no work. Other options as well. Like extra for high bandwidth stuff(voip, videos) this isn't about download limits. It's how much you transfer per second on the pipe(something they still offer unlimited(or as high as technology will go) here).

Plenty of ways for them to make money from data and voice. They just don't want to just like any other established industry.