I'm surprised they didn't bake a deeper integration with Facebook profile and photos instead of making Instagram more Facebook-like with potentially competing features. As a user I do think this is the right approach to keep both services running as separate networks, but in the long term I'm not sure if operating as independent kingdoms will be sustainable if they continue to merge closer in features. Facebook Camera now offers filters, Instagram now has profiles in browser... Maybe its own news feed next? Not to mention profile and news feed fatigue that could hurt engagement for both...

But that's all cynical speculation, congrats to FB and Instagram for not killing off Instagram. My gut says that's the right decision.