Why would Connecting Devon and Somerset / Openreach only fibre enable (from Ilminster) just over half of Chiselborough exchange subscribers (WWCHIS) and in fact virtually everyone in Chiselborough village itself won't get it?
PCode TA14 6SG and TA14 6SJ for example and map
WWCHIS Chiselborough - which serves Norton sub Hamdon, Chiselborough and West/Middle Chinnock.
We lobbied both CDS and BT to get this over the last 20 months including training supplied by COSMIC at CDS's expense and have a database of about 1/3rd of the subscribers and it 'seemed' to pay off as Openreach have been feeding cables through ducts ready to blow fibre through. There is one such duct outside my house (TA14 6SJ) which is just outside of the orange colour on the map and there is a cabinet just 60 yds away up New Road which is definately out of the orange part of the map.
Why would CDS / Openreach bring fibre to an exchange and alienate about half the subscribers in it? In fact if you look at almost all the surrounding exchanges you will see that WWCHIS stands out as both tiny and to be fibre enabled Oct 2014 at least 'some parts' the remainder will have to wait another year?
You may find that CD&S/Openreach are also debating about whether to install a new PCP and FTTC Twin opposite the exchange to serve E/O lines - This has been very common in our area at least and can serve a very large number of users. I'm not entirely sure whether this appears on any map either because it's a brand new PCP.
As others have stated though they have definitely got some attention on your area as work is going to start soon.
Current news for Roadworks:
Roadworks planned on Cat Street in Chilselborough (Your exchange) which will install a cabinet and base with ducts due to start on 20th Nov and end on 3rd Dec.
There's also roadworks planned on Skinners Lane in Norton Sub Hamdon for installation of 100m of cable (No specification as to whether it's fibre cable though) - Due to start and be completed on September 22nd.
As for why they would "alienate about half the subscribers in it" it depends on the infrastructure - On a smaller exchange, things are usually more expensive and can require more specific planning/solutions. E.g. If a cabinet only has 20 subscribers it could be more cost effective to deploy a different solution.
Anyway your area is earmarked
Telewest (2004-2006): 256Kbps -> 512Kbps
University of Portsmouth's Horrible Network (2013 - 2014) - Supposedly 100/100Mbps
BT (2006 - Present): 8128/448 -> 22494/1211 -> 79987/20000Kbps (BT Infinity 2 on Huawei Cab)