Daftpunk - you say that Riven was not in possession of all the facts - but how could she have known that David Cameron was going to make this announcement? The date on the link in the OP is the 18th of August - and I believe Riven's thread was started well before that date - hence she couldn't have known he was going to make the announcement.
For all we know, Riven's thread may have been what jolted him into remembering his promise to her, and spurred him into making the announcement.
And since all he has done is said that the PCTs should stick to the guidelines - that people should be given sufficient for their needs - and that no arbitrary ceilings should be applied, I can't see that he has actually done anything concrete.
Each person/carer - like Riven - is still going to have to slug it out with their individual PCT, and force them to stick to the guidelines - and anyway, they are only guidelines, and PCTs can ignore them, because there is no force behind them.
David Cameron needs to say that each person like Riven's dd must get sufficient incontinence products to meet their individual needs, and that the funding will be provided. Then he will actually have changed the situation that Riven and so many others are in, rather than just reiterating the pre-existing guidelines.