@piezo It crossed our minds, too.
It is just one variable in the code but I guess that would be a soft fork. Edit: It would be a hard fork
If someone pays 0,1 Burst per transaction (possible in a new version) or 1 Burst per transaction and the Block is 'full' ... the higher fee transaction gets processed first. The lower fee transaction has to wait until in the next Block.
I guess we are fine for a long time. Till 1 Burst 1 penny at least to start a discussion. In general our fees will always be lower than bitcoins, because the operating costs (OPEX) of the whole network are much lower.