So I remember there was some discussion a while ago about how eventually some bitcoins will dissappear (people's computers crashing, people dropping out of bitcoin, MenInBlack collecting as many BTC as possible to drain them out of the system etc).  And it's still not clear to me if this will eventually be a problem or not.  Clearly, if the number of bitcoins will stabilise at close to 21 million, no problem, but if BTC loss is serious, then it may impact the economy.

So, one of the counter-arguments was that a new proof-of-work chain could be trivially started, with a whole new economy.  "BTCv2" let's say.  Well, there are a couple of problems.  First of all, everyone who has BTCs will be really pissed off that suddenly their BTCs are valueless because everyone wants only BTCv2s.  Second is, I think, a more serious problem, but then maybe I just haven't understood the coin generation process correctly, and it goes like this: bitcoin is a once off experiment.  If you decide to start a new proof-of-work chain for BTCv2, then all I have to do is get all the old BTC proofs-of-work, and add them to the new chain, and I'll instantly have lots of BTCv2s to my credit.

Problematic?