There are other cryptocurrencies like [1] that propose to connect the money supply to the number of users, so that the first emitted currency unit has the same value as the last emitted one.
I'm not familiar enough with cryptography and economics to fully understand the risks and benefits of this kind of currency.
So, are you also concerned with the bitcoin's capped supply? What do you think of the alternatives?
[1] http://project.openudc.org/