I'm not so sure. The reason was by the time it was "discovered" you had people denying it. Plus just the thought made someone jump out of 600 btc, other websites showed they never moved and that probably stopped a much bigger route. Currently satoshi owns as many bitcoins as gox did at its highest. (7%). If those coins ever move, that would be huge. Especially if they started getting sold on an exchange. The sell would weigh on the price, others jumping out would do the same, and who knows how that could end. Personally Satoshi's coins are a massive weight around the neck of bitcoin. At this point they should probably blacklist those things, if only to remove the "what if" scenario. I mean if 600btc is enough to drop the price $2, 1.5 million could certainly drop it to zero. Bitcoin demad is ~1 mil per day (3600×285) that is laughably simply, but still probably the best guess. That means it would take 400 days of demad for satoshi's coins to push through. Assuming no other coins came into the market

For further perspective consider that 7% of all Microsoft shares are held by company insiders, and MS employs about 100k people, and has a crap ton of liquidity on the open market.