Unfortunately I have to agree - I asked the same question of a CAA FCL rep last year and was told that there was no demand so it probably would not happen. The NPPL only came about because of intense lobbying pressure from the PFA et al, and there is just not the same pressure from the rotary community due to the lower numbers.
It is not so much a question of 35 hour helo pilots - I have a PPL(A) and a PPL(H) but an NPPL (A) would be perfectly adequate for my fixed wing activities (day VFR in the UK). Were there to be an NPPL(H), this would also be adequate for my rotary activities. The big difference between the two is the reduced medical requirements, ie for the NPPL you only have to have an HGV equivalent certification every 5 years I believe. At my current age, I have to have the full Class 2 JAR medical every year just for the rotary licence, otherwise I could drop back to the NPPL for fixed wing and save the annual cost and hassle.
As I am no more likely to cause an accident through possible medical incapacitation in a helicopter than I am in an aeroplane, I fail to see the need for the full Class 2 medical for one licence and not for the other.
But as I say, it is unlikely to happen. There would have to be an industry push to attract more budding helo pilots, and this does not seem to exist, possibly because the entry cost is so much higher.