Every word of that post made sense to me until you said 'last port of the cable plant' -- how is that relevant to distributed bandwidth?
I pay quite a bit for my internet access, as it is no longer subsidized by my employer. But the service is pretty good. There's a download limit but I blame myself and everybody like myself who downloads a lot every month. The funny thing is I don't download any more, and by Sept I don't expect to ever run into problems with that (I used to go over the limit and they charge you an arm and a leg for moar).
All the same, I don't remotely get close to 50 Mbps and so I'm jealous. Also I didn't think such speeds were possible except in other countries like Japan...wow