Logically if you are close to the exchange the demand for FTTC will be less than in areas where the maximum speed has only ever been less than 2Mb/s!
Demographics will come into in - middle and upper income groups are more likely to spend the money than lower income groups, older people (over 65 or so) are probably less likely to have ADSL in the first place.
Number of telephone lines in the PCP compared to the number of slots in the FTTC CAB is the key. If they put in a 128 line FTTC CAB and the PCP has hundreds of lines then they "may" go quickly, if it is a big 288 line FTTC CAB and a smaller number of telephone lines this seems less likely.
BT have been known to revisit sites where the space in the FTTC CAB has all been used but obviously it will take a while.
Under "normal" cicumstances you "should" be alright as many people talking about FTTC are waiting to see what happens and a huge majority of users still dont know what it is anyway!
Ex <n>ildram , been to SKY MAX - 15,225 Download
BE Unlimited - 21,000 Download 1,200 Upload ON THE LINE THAT SKY COULD ONLY PROVIDE 15,255 DOWN AND 800 UP ON!!!,
Moved house, now BE Unlimited 6,500 Down, 1Mb/s up - gutted!
FTTC Cab installation commenced 12th April - expect full 80 / 20 - bye bye BE, hello BT Infinity soon!