At any point, Satoshi's coins could move without warning and be recirculated in to the supply. As could any coin which is considered "lost". We have no way of knowing how many coins are truly "lost", and everyone (at least everyone who understands bitcoin even a little) should know and appreciate this. Having a sudden influx of a million coins, and therefore a ~5% inflation, would be less damaging to bitcoin than removing one of its core principles by allowing a small group of people to decide which coins are and are not allowed to be used in the future.

Still, if suddenly a million coins moved from early addresses, I suspect the price would dip more from weak hands panic selling than from these "lost" coins entering the market. An attacker with the knowledge and technology to break ECDSA isn't going to be stupid enough to dump a million coins on the market at once. If these coins do move, I'll be waiting to buy the dip.