I've had in the back of my mind an idea for a long time that will take alot of ingenuity to implement, but I'm fairly confident it will be the kind of electronic currency that will sustain itself well after bitcoin.
The concept is based on the idea that there is no centralized or distributed mechanism for determining who has "mined" the currency. Each individual just creates an account, and over the lifetime of that account sustains itself based on comparisons with others whom they've transacted with. The algorithm would need to adapt to attempts to defraud it, but think about this.
If I am transacting with someone who has been spending the currency like a mad man, their currency can be seen as less valuable to the overall population (since they may be a statistical outlier in usage of the currency). When someone has spent too little, this can also be a negative, since new and unestablished accounts mean the person may be less trustworthy, etc.
I think the key to this may be in the ability to tie an account to a person's real identity somehow.
The concept around it really puts everyone on even footing when the currency first hits the market. None of this madness. Sure you can probably make money for a while with Bitcoin, but I'm not willing to bet too much on the long-term sustainability of it, just because it will be like most currencies in the past. Some will start with alot, and some will be left out to dry with none. It's simply not as appealing as a self-regulating currency.
There are fewer than 11.5 million addresses in use, so fewer than 11.5 million people have any BTC. There is a lot more growth to come.
Peter Blodget in the PandoDaily talk was pretty pessimistic about it. See: pandodaily.com/2013/11/18/blodget-and-the-rarified-air-around-bitcoin/
I, for one, am somewhat pessimistic about it since it doesn't tie to a national currency. Noble cause, but naîve, IMO.
Tech is about creating value for the long-term.
Seriously, though, you need to predict the behaviour of others - will they think that it is going up?
I bought a small amount now. Total speculation. Not enough to ever make a difference to me. I guess I'm like an entrepreneur who got heavily diluted.
My total guess is that there is a lot of pent up demand right now. A lot of tech people have already got into it but a lot more "normals" will take time to figure out how to get into bitcoin. Again, my guess is that it could collapse once the last of the "normals" has gotten theirs. Some chance there will be a day trading platform come out of it. Some chance it will become a lot bigger ... global currency level big. Who knows?