This is all fine and dandy, but...
The exponential trend based on number of users, even a super exponential trend (x^4) due to increased usability with more users, is probably sound and it is what I use for my own long time view. But the line is distorted by speculation (which is the same as foresight).
Personally, I believe that the theoretical exponential line is positioned far below the historical trend, maybe at only one dollar per bitcoin as of now. The reason is that the early adopters including myself, are leaning towards saving, and taking advantage of the implementation phase, but the majority, when they come aboard, will think more of the practicalilty of indirect exchange. After all, a lot of people have only about 1K of USD as ready money.
So even if the exponential baseline is sound, we don't really know the future.
