Here is an analogy. I don't consider Klingon, Esperanto, or Latin to be real, living languages. They fill all of the requirements of being a language but people can't live their daily lives using these language and they don't think in these languages. Books may be translated into these languages, but few books are written in these languages. Native speakers are rare. Latin may be an edge case.
Yes, you can do a lot of things with BitCoins. But form the posts that I see on Slashdot, these retailors are immediately converting the BitCoins to the local currency. That suggests to me that the BitCoin economy is a mile wide and an inch deep.
As for BitCoin, I am not rooting it to fail but I think it will. From a technically aspect, it has many virtues as a currency. However, anything that acts like money is money. In good times, many things can act like money but in bad times the amount of money can contract rapidly. Hence monetary policy. BitCoins lacks that flexibly. I personally feel there is going to be a crisis and the whole thing will collapse. Now, on the flip side, hard money types will tell you this inflexibility is a virtue.