Tyvexx]Well regardless if it's a fiber connection or not it has to terminate on a CE router of some sort before being routed through the networks backbone. They most likely do the same thing you see with your current cable infrastructure, and have a customer fiber switch for each designated area of service. Those switches/routers tie back in to their network before being sent to the routers provided to them by their upstream ISP/NAP.
Ahh the glories of the interwebs.
Actually you would be surprised. Most companies offering that sort of bandwidth are running off the backbone regardless. For instance, we have Mediacom here with 20Mbit download speed. Of course, since most sites are using bandwidth filtering, the most you could get is 500Kbps. From the DF patch server, 2Mb/sec (the whole enchilada).
Ping times, of course, are graciously increased. 110 ping time when we were on EU (From MO).