Access isn't the problem, backhaul is
100Mbps to houses only makes sense if the contention ratios are sensible. Such a service will only appeal to people spodding away with BitTorrent, as there's hardly any other compelling services, so the utilisation will be high (although quite why people need to download at a rate greater than 24 hours of TV per day is a mystery to me). Running ADSL 2+, fibre or whatever to houses is the easy part: the ISP will be committed to 10s of Gbps from the exchange (or its equivalent) to their metro nodes (your typical LLU operator will have one GbE equivalent), and will need to get 100s of Gbps of Internet peering from somewhere. This isn't cheap, and it remains to be seen how large the market for this sort of stuff actually is.
I work in ADSL equipment manufacturing, and the lunchtime conversation is usually about what compelling services there are to drive adoption of higher data rate. Legal, illegal, cost-effective, not cost-effective, to an extent we don't care, just so long as consumers press ISPs to go to higher data rates we'll be able to sell kit. At the moment, when most people can't get the datarate their line is capable of for reasons deeper into the network, it's a hard sell.


