1. This is great, throwing it back to government for the people and really should shake up big federal governments.
2. Or maybe not so great, because of number of pitfalls. Getting something like secession right is hard, chances are economies will suffer hard. There will be some superpowers that will never allow this is current political climate such as China, Russia, and potentially India. This will be effectively strengthening their positions. If countries split up into smaller states, while local governance will likely improve, international gridlock will not.