(we really need to do something about lost coins btw, no?)
No.
That's true. It really doesn't matter. It just makes bitcoin more rare for everyone else and even more valuable. This, combined with unlimited potential subdivisions of a single bitcoin, and there is no problem. Just don't be the idiot to lose your own money.
How can it make it more "rare" if we can't determine how much of the bitcoins are actually lost? How can you tell if an this address has a lost key or a parked key, in a vault somewhere?
The whole subdivision thing is interesting if it can be pulled off.
What makes the difference is basically the amount of bitcoin available in the open market. As available supply goes down, that is what going to make the price goes up. It doesn't matter whether we need to know or determine how much bitcoin are actually considered lost.
