Again, like Picard said, “I think we can all exercise some self-control”. Meaning, sorry, no authority, no one to hold your hand. Common, do you need your mum to call you up and tell you when to go to bed? No, you’re an adult, you can take that responsibility yourself. That is what I mean with a maturing of our culture - that we must learn to act like adults and take responsibility. You don’t eat a pound of fudge just before dinner without anyone telling you because you know it’s not good for you, just like you don’t steal from the honesty bar even when no one is looking because you consider it petty and wrong. In the same way, you don’t decide you want 15 cars and a golden yacth in a anarcho-communist society.
I enjoyed reading your post, maybe 'cause I’m a bit buzzed too… in a way I hope this discussion dissolves into a drunken Picard vs. Kirk nerd-off 
Regarding the point you make, it does not apply in an anarchist society. See me previous post about the rejection of Cartesian rationalism (and with it, central planning). This is exactly why, because there can never be an optimal solution. You always make some sacrifice.
The whole point of anarchism can be said to be that “decisions ought to be made by those affected by them”. That is the answer to “And who is to say what the right thing to produce is?”
What you eat, what music player you listen to, etc, should be decided by you and you alone. Communal decisions, like “do we build a sports stadium or a hospital”, things that effect an entire community, should be decided by everyone in that community.
Same goes for investments of resources into research and new inventions. Maybe we wouldn’t have iPods, maybe we would. The point is that the decision to research a better music player would not be made by a corporation because they see a window for profit - it would be made by the people affected by that decision. So maybe you’d have a situation where you can’t fit every song ever made into one mp3 player, but you’d have better medicine.
An anarcho-communist society would in essence be a “polis” as described by Aristotle (though he did not acknowledge the need for freedom, bear in mind!). The “best good”, a bundle of all possible goods relevant to human happiness subject to human needs, as we understand them through science (psychology, neurology, anthropology, sociology, etc…) and philosophy; containing the fulfilment for all physical, mental, moral, personal, spiritual, etc. desires.
There is room for individuals to choose differently; this reasoning fully supports pluralism, as it is perfectly possible to have different life plans, ways of life and cultures, that arrive at different bundles of goods, which are still coherent, admissible and admirable.
The price mechanism guides us - to more profit. That is the only thing it can do, the only information it carries. The price mechanism cannot help us make environmentally or ethically sound decisions, unless there are monetary consequences. As Mises himself admits:
“If… we are considering whether a hydraulic power-works would be profitable we cannot include in the computation the damage which will be done to the beauty of the waterfalls unless the fall in values due to fall in tourist traffic is taken into account.”
That is why you wind up with a world with wanton ecological destruction; “If we know precisely how much we have to pay for beauty, health, honour, pride, and the like, nothing need hinder us from giving them due consideration." (Mises) Things only matter if they have a price tag. It may “pain” some “sensitive people” but hey, "it is in the nature of things.”
Furthermore, only the subjective opinions of those with purchasing power matter to the entrepreneur. This is why you wind up with a world with a kick-ass entertainment device like the Wii, and millions of people starving. Those people have no money, so their desire for food is nothing compared to my desire to play virtual bowling.