From a technological standpoint the incentives of mining and maintaining full network nodes have led to the first implementation of a public shared data store. Neither Bittorrent, Freenet, nor DHTs of any sort satisfy the conditions of being public, having equal access read and write privileges and data that is always available.
You can't have the benefits of the blockchain without the incentives that the units can operate as a currency and be traded for other things of value. That's what keeps everyone validating and making the data publicly available.
The politics are a completely different beast. The anarcho-capitalists and other anti-government proponents who have claimed Bitcoin as their own are living out a fantasy.
I don't think that Bitcoin is going to be the downfall of the nation-state. I think it's going to allow for some very interesting types of software to be made.
Please don't conflate Bitcoin as a technology with the mad ramblings of a bunch of basement dwellers.
But where Bitcoin falls down is in the long term model of currencies. Currencies should only be a medium of exchange, not a long term investment vehicle. We want people to spend or invest money in useful things rather than hoard money. Bitcoins deflationary model encourages hoarding, which in turn diminishes the amount of currency in active circulation, resulting in a sub-optimal medium of exchange.
I think the general currency or commodity aspects are of less importance than the public ledger.
It's a kind of currency that's main use is in being able to write to a public data store. The most basic data that is stored is value transactions but anything could be stored.
You should really think about it in terms of the kinds of incentives that drive our information economy.
Take a look at Twitter. It operates as a sort of public broadcast medium yet the way that it stores and retrieves leads to vast information asymmetries. Information asymmetries lead to economic asymmetries. Such infrastructure is very costly to operate and leads to perverse incentives to monetize. The information economic model is flawed.
Bitcoin was developed from the ground up with a functional information economic model, regardless of the political expectations of the developers.
The same can be said for Bitcoin believers who, in the face tremendous of evidence otherwise (BTC volatility, pleas from respectable folks who study currency and economics, the types of shady characters BTC has attracted), believe it is anything but a flawed implementation of an interesting but possibly bad idea (the blockchain).