This is clearly illuminating the Ponzi-like elements of Bitcoin. As in a Ponzi scheme, early arrivals to the system earn easy money, funded by later arrivals. Tales of bitcoin fortunes draw more and more entry to the system, leading to large payoffs for second stage arrivals, attracting more speculators due to the media attention and very real money that has been made by early players. This continues until, oh, wait, bitcoins aren't so easy to mine anymore and there's no new wave of incoming money to pay of the next generation of miners.
The hilarious thing is that Bitcoin is quite transparent about exactly how it works, while a real Ponzi scheme goes to great lengths to hide this dynamic. Anyone can see this dynamic in the rising price and the increasing CPU time needed to mine a new coin. And yet, brilliant, savvy investors like the Winklevosses are somehow still getting involved...