There seems to be a massive confusiuon here. What isn't
feasible is end-to-end telco-style metering, which is what
those articles all about. (Actually, anybody who ever made
international calls knows that telcos also cannot do complete
metering and simply ignore load on in-country circuits).
Metering on customer access lines does not change economics
of backbones at all (where all the real hard problems are).
In other words, the access line metering is irrelevant to
what is discussed.
Generally speaking, at least 70% of users already have metered
access of that kind (in form of per-hour connect time charges),
so in this sense Internet is metered already, and was like that
for years. Obviously that's not "metering" Metcalfe et al
are calling for.
(BTW, i know providers who do attempt to charge differently
for local and international traffic by counting packets,
but they have developed quite a lot of software and have the
financial and legal framework to support it. The fact that
they don't have anything faster than E-1 helps a lot, too.)