Thanks, you made the point i wanted to make.  I'd just add that the existence of bitcoin may have a stabilizing influence on fiat currencies due to competitive pressures which are likely (but not guaranteed) to develop.  It might "keep them honest" to a degree.

If this happens, then bitcoin growth may slow as bitcoin will only hit sectors where it has an uber obvious competitive advantage such as international transactions.

If however the USD is driven deep enough into the hole, then hold on to your horse - it will be quite a ride.