Peter writes...
In the end, there needs to be a set of business models (probably more than one) that are good for both the customers and the providers. I believe usage based models will be there for the reasons cited above, and the fixed rate schemes will be employed where there are broad averages that can be exploited (the customer likes the flat predictable rate, the provider believes the average usage still allows him/her to make money).
However to ground this discussion into a hard reality the fact is that there are precisely these business models already in existence on the Internet today. Typically you see metered accounting structure where there is multiplexing of the resource (modem ports or high speed trunk bandwidth) and flat rates where averaging can be used. Of course quite frankly even flat rate schemes worked off access bandwidth are metered. Its just a big meter bucket. a 64K access pipe can deliver some 21G per month. So charging a flat rate for a 64K access is equivalent to charging for a 21G volume of traffic (or part thereof). So another spin on this is that the issue may not be one of metered or unmetered, but simply a discussion on the size of the metered unit. Geoff