My prediction is that this era of free public relays will be short lived lest we fall victim to the tragedy of the commons.

Second prediction is that as nostr grows, there will be clients that are also lightning wallets. This part sucks because they will likely be custodial. If nostr grows beyond bitcoiners, I think someone will see this as an obvious UX improvement to onboard non-bitcoiners who don't want to learn two new things (nostr and bitcoin). I'm not happy about it, but I think this is where things will end up.