GB Studio, upvote.
Cool people writing their own emus, upvote.
Analogue Pocket, upvote.
My sincere wish is that one day Nintendo somehow, someway, open up legitimate Game Boy publishing for third-parties again. Release the patents, allow developers the use of the Nintendo logo in the one very very specific place it's necessary to allow GB games to boot, etc. Maybe open sourcing schematics and internal docs.
But that's as likely as them releasing a (new) Mario game on PC...
For me, the GB is that perfect middle ground between too arcane/simple and too modern/complex (both the design of the games and in the programming required). If the platform were opened, it would be kind of a "forever console." It would obviously not compete with new systems or anything like that, so it would always be pretty niche.
It would be a fantastic educational tool to get kids into programming and game design at various levels.
Maybe in another 20-30 years...