I see another problem with bitcoin which is the price of it. I know it is divisible but nobody wants to deal with long numbers for small transactions. I mean right now, to send a $1 via bitcoin, I've got to deal with this very long number which isn't friendly at all. Now if they want to call that number satoshi or whatever then that's fine but if I've only heard of bitcoin then I don't know satoshi.
The real question is have the network effects enabled bitcoin to "break out" in some significant way? That's the real test because right now functionally bitcoin is way of transacting over the internet, rather similar to pay pal and like pay pal it is useful but has limited value. I could use google wallet or some other service. However, if bitcoin is accepted by enough places then it takes on a new nature, at that point it is no longer just a way to "send money" or do ecommerce. But, at that point it becomes the dominant currency.
There are no more conversions. So, that would be powerful. I could send bitcoin overseas but that person doesn't have to convert it. They just spend the bitcoin at another bitcoin accepted establishment.
So, to understand whether or not bitcoin is viable we need to look at other networks like Facebook and MySpace. The value of bitcoin other then being a hindrance to its adoption has little to do if it has reached the network potential.
So we need to compute the value of bitcoin based on how many businesses accept it. If one desire one can compute a ratio of the value of bitcoin to the network value to see if they are moving in tandem or if it is a speculative bubble. If the value of bitcoin has grown much faster then network value then bitcoin can be said to be over priced. You want to buy when the ratio is historically low.