I've thought about the possibility that once the block rewards get lower the mining could transitions back to smaller communities and groups, but we've already had blocks where the fees were more than the reward... so prob not. Maybe each community that runs a mint also runs some miners. I could see it making sense IF the fees are lower and that way the mining stays active and you have people with incentives to keep things working well. I guess we'll just have to see how the financials work out over time.