For what Ether aims to be for (ultimately the token for the Ethereum platform), the token itself must be adaptable.  When it began, it had an infinite inflation rate of 18 million a year - though as gas was burned, the supply would be reduced.  The community is evaluating this now and the reason is simple: is this a good model for a token that must be used for Ethereum?  Will this work with a POS future - if they definitely go this route?