I have been lurking for a while but this is my first post.
From what I hear there will be no movement on PPS14. The local planners already had similar powers to refuse applications in the open countryside under existing policys; however, PPS14 just seems to have packaged them together and made it mandatory that they use them.
I have been told that (no evidence) Omagh district council (who broke the news of PPS14) has a room full of applications for outline planning which have to be decided under old policys and will likely get approval (because of precedent), I believe this is the same for all local authoritys. In the next number of years we will probably see an increase of sites on the market.
A lot of sites with outline do appear to be running out and are being extended with a full application, I believe that this reduces the price of the site as most of the full applications are awful design. PPS14 does allow for the change of house type or a full application which does not confine itself to the outline conditions although it can sometimes be an up hill struggle explaining this to planners. (they seem to be as confused on the subject as the rest of us)
I spoke to a number of local estate agents recently and they have suggested that sites are on average going for 10% less than the asking price at the moment. One EA also suggested that he expected more than 20% falls in new build developments.
Anyway I realise that you are trying to stick to facts on the board at the moment and this is all just my opinion with no evidence to back it.