Probably just exchanges that still just had 1Gig links, and will be moved to 10GigE very soon.
I suspect part of this may be a balancing act going on between not wanting to order (and pay for) unnecessary capacity, and the lead time for upgrading backhaul circuits - though the issue in some areas may be unavailability of 10GigE circuits. I would have thought that increasing data volumes make it a 'no brain' decision to aim to upgrade backhaul to 10GigE in advance of offering FTTx. If this backhaul is via a managed circuit which has bandwidth charges, it should be relatively cheap to upgrade the bearer to 10GigE and enable extra capacity as required with relatively short lead times.
I'm always amazed at how loudly people complain in stories in The Register and similar about outages on cheap consumer ISPs when their expectations are unrealistic. If you're taking overtime to work from home, you should have two different forms of Internet access that are as diverse as possible - one of these can be tethering a mobile phone or a PAYG mobile broadband dongle, so may cost very little if rarely used. Internet access matters to us - we've got Zen FTTC, my contract O2 mobile broadband account and I can tether my contract Vodafone mobile phone.
I've considered putting cheap consumer ADSL on our other BT line so that I can implement auto-failover on my router. This would protect me against failure of the FTTx system, also, if I choose a provider using LLU, against a BT Wholesale outage, though not against failure of the twisted pair network between the PCP and our NTE5s. The other alternative would be seeing if Virgin are prepared to add their cheapest broadband product to our cable account at minimal extra expense, though I was most unimpressed with cable broadband when I had it.
If quality of service matters for home working, I'd think there was justification for your main ISP being one of the business orientated ones (such as AAISP, IDnet or Zen). These providers don't operate on such tight margins, so have more of a cushion to try their best to ensure users don't experience contention serious enough to cause packet loss or excessive jitter.
Edited by David_W (Tue 22-Jan-13 20:51:48)