Actually it sucks and is getting worse. The NBN map looks great but if you look carefully, it "covers" the reservoir and not the street opposite. New providers with their own towers and dish but as of the time of writing no line of sight to me. Odd, I can see all the hills!
Dernancourt will be part of a future rollout plan of NBN, maybe for fixed wireless. But if the area is congested and wholesale providers can no longer offer ADSL, then you might get NBN Satellite by 2016 once it's launched.
Not great given its serviced from the Hampstead exchange. ADSL2+ will be at best about 2.5Mbps service from an 24Mb offering. Cable is there obviously but for many that is not cost effective. We are about as far from the exchange as you can be and that's not a positive thing for Internet. Its also about 10Years on the NBN schedule.