Yesterday I was talking on IRC with somebody who took a few more economics courses than I did. He was very concerned by hoarding, which would possibly make the early adopters stupidly rich. We agreed Shatoshi cashing out would probably signal the end of bitcoin.
The bitcoin days destroyed metric doesn't support the idea that there are enormous amounts of horded coins a good a mount of coins are moving around.
I also don't see why people assume Satoshi has some enormous number of coins bitcoin was made public as soon as the chain started (and had been discussed in public months before, so people knew what it was when it was announced).
He was far from the only user when bitcoin was announced if he was only mining with a single modest cpu of mid to late 2000s vintage he might only have a few tens of thousands. This guess is actually well supported by the initial data bitcoin had enough hashing right at its launch to maintain 1/block per ten minutes but actually fell to what should have been difficulty .05 in late august 2009. Because the system can't adjust to difficulty below 1 this loss of hash power just mean less coin was created overall. If you make the somewhat conservative assumption that the remaining miners included at least Satoshi and that he had similar hash power all year, then Satoshi could not have more than 5% of the first years bitcoin and very likely he wasn't the only remaining miner so that 5% would have been shared between everyone else who was still mining during the lull (and there was less coin produced in 2009 than programmed due to the time spent with hash power below diff 1... about 60% of what the system is programmed to produce in a year). The large gap between block 0 and block 1 (when he made the system public) also supports the notion that he didn't have a ton of hash power applied.
We often view the early difficulty through the distorted lens of todays faster hardware and software. This is a mistake. modern mining software is an order of magnitude faster than openssl's SHA256 used simplistically, and modern CPUs are also much faster (not to mention GPUs...).
