For all its usefulness, the distinction between doctrine and policy has its explanatory limit, and one reaches it rather quickly. For one thing, it's impossible to make an a priori judgment on whether a particular practice is a doctrine or policy; they all look the same in the present, and it's not until something changes that we apply a post hoc "policy" label. How, for instance, can we tell that the restriction on women's praying in Conference is just policy? If anything, there probably is a decent scriptural case against women's praying in public. On a philosophical level, it has been argued that Mormonism as a system of ideas effectively demolishes the series of binaries on which the doctrine/policy split is based. Time and eternity, human and divine, sacred and mundane: Joseph's restoration proved these contraries and found their most fruitful expression in radical juxtaposition. If this is so, then a heuristic that relies on rigid binary distinction, like the doctrine/policy split, probably will not provide the deepest insight into Mormon experience.
Despite these limitations, the distinction between doctrine and policy has one great virtue: it allows Latter-day Saints to extend the scope of their teachings and practices in the modern world while maintaining the vital connection to our rich history. For Mormons, history is the first draft of theology: we mine our past for insights into God's will and nature, for tools of social organization, for answers to vexing personal and institutional problems. By explaining the eddies and by-ways of our history as mere "policy," we preserve our collective trust in core "doctrine" and, crucially, we look back in love to the Saints who came before us and the institutions and practices they put in place. To poison our relationship with our past would be to irreparably impoverish Mormon experience.
So even if the doctrine/policy distinction has its limitations, it nevertheless does good work in certain LDS conversations, and I think that Cynthia's is one of those. In any case, Cynthia's suggestion to invite women to pray in General Conference seems perfectly suited to Church leaders' preferred style of forward motion since President Hinckley: it is incremental, it is more symbolic than structural, and it is humanely inclusive whenever possible. I think it's a great idea, and I would certainly welcome that invocation.