I quite like the idea of Bitcoin, but let me play Devil's Advocate.

It seems that Bitcoin's only value is its ability to be converted into fiat. That guy never would have sold his Porsche for 300 BC if he couldn't cash out via Mtgox.

If the above is true, doesn't that make BC a commodity? A commodity that has no intrinsic value?

How can things on the supermarket shelf be priced in BC, when the 'price' of BC changes so much from day to day?

How could it possibly transition into a currency that doesn't need to be backed by anything?

Is the best we can hope for is that BC remains a temporary place to store fiat and pay for things anonymously?