Hi Pintosal,
My understanding needs confirmation, but here's my take on the situation. (Others please comment)
Firstly I don't think anything will change before you pay BT for a better service.
When you do pay I believe your line will be connected using SMPF (Shared Metallic Path Facility) which in human speak means an ADSL filtering arrangement is used in your FTTC.
In real terms the line from your house will still terminate in the old PCP. It will be disconnected from the E side cable to the exchange there and connected into the link cable to the new FTTC, then a second pair in the link cable will return the phone part of the cct. and be reconnected to the existing E side pair, assuming nobody makes a mistake in the process.
Also assuming your D side line remains in good condition and as it is so short, you should get a substantially improved connection at some extra cost. The usual caveats re contention etc. still apply.
Note this differs from the Rutland solution which uses FMPF (Full Metallic Path Facility). This method diverts your D side phone line direct into the FTTC and is terminated (and isolated) there. Rutland then provide a full VOIP service sending your voice data over the internet connection to a VOIP service provider.
With the BT solution I believe you will still have to pay standard line rental as well as your broadband fee, but with the Rutland solution one single payment to them covers their call charges and sub-loop unbundling rental and their broadband fee in a single payment.
Note also this FTTC VOIP differs from the current e.g. Zen type VOIP where the outgoing calls are sent via their internet connection, but incoming calls are still routed via the old BT PSTN.
It's all very simple when you know how, but just try explaining this to the population !
Kind regards,
Walter