Thanks for your replies.
I want to give my opinion here.

I think a good way to circumvent this problem is to not to limit the amount of BTC to 21M. Instead it should have a deterministic inflation rate of let's say 1%. This would have 2 benefits:
First the concept of mining as it works today could go on for ever. Secondly, deflationary forces such as loss of BTC, could be compensated for.

I general inflation as it is today is not a good thing cuz it takes monex from the savers to the speculaters, but if the inflation rate is small and deterministic it would be a good compromise.

What do you think of that?