Well, I used the term "inflation" as a synonym for the rate of change in the total monetary supply. Obviously, in a fast growing economy increasing the money supply by 1% per year may actually translate into price deflation.
In any case, increasing Bitcoin's money supply in a fixed pre-determined rate is actually trivially easy. If, for example, you want the increase in money supply to asymptotically approach 0%, all you have to do is to let the block mining reward forever be 50 BTC. Therefore, there is nothing in Bitcoin's architecture that prevents the usage of a different algorithm for increasing money supply.
In fact, I think it is very likely that we will witness the emergence of a competitor to Bitcoin that is based on the same architecture and crypto (perhaps even forking the same source code), but whose sole difference will be the elimination of the 21 million coin hard-cap. Though most hardline Bitcoin supporters will dismiss this alternative system as doomed to fail because of the built-in inflation, I suspect it may actually succeed because people will be more inclined to use it as currency instead of just hoarding.